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A
NEW SYSTEM
OF
CHEMICAL PHILOSOPHY.
' PART FIRST.— VOL. II.
NEW SYSTEM
OF
CHEMICAL PHILOSOPHY.
PART FIRST
OF
VOL. II.
BY
JOHN DALTON, F.R.S.
President of the Literary and Philosophical Society, Manchester;
Corresponding Member of the Royal Academy of Sciences, Paris;
Member of the Royal Academy, Munich, and of the Caesarean
Natural History Society, Moscow ;
Honorary Member of the Royal Medical Society, Edinburgh,
and of the Philosophical Societies of Bristol, Cambridge,
Leeds, Sheffield and Yorkshire.
Printed by the Executors of S. Russell,
FOR
GEORGE WILSON, ESSEX STREET, STRAND,
LONDON.
1827.
TO
JOHN SHARPE, Esa. F. R. S.
OF STANMORE, MIDDLESEX,
(Late of Manchester)
AS A TESTIMONY OF HIS FRIENDLY REGARD, AND OF HIS
LIBERAL ENCOURAGEMENT GIVEN TO THE PROMOTION
OF CHEMICAL SCIENCE:
AND TO
PETER EWART, Esa.
Vice-President of the Literary and Philosophical Society
of Manchester,
ON THE SCORE OF FRIENDSHIP,
BUT MORE ESPECIALLY FOR THE ABLE EXPOSITION AND
EXCELLENT ILLUSTRATIONS OF THE FUNDAMENTAL
PRINCIPLES OF MECHANICS,
IN HIS ESSAY ON THE MEASURE OF MOVING FORCE^f
THIS WORK IS RESPECTFULLY INSCRIBED BY
THE AUTHOR.
+ Manchester Memoirs, Vol, II. ( second series. J
PREFACE.
J. HE work now submitted to the public was begun to be
printed in 1817; and the 13th and 14th sections, containing
the oxicles and sulphurets, were printed off before the end of
October of the same year. The printing of the rest of the
work to the appendix was finished in September, 1821. One
sheet of the appendix was printed at the end of 1823 ; but no
addition was afterwards made till May, 1826 ; when the print-
ing- was resumed, and has been continued to the present time.
It may be asked, what were the motives for such a plan of
procedure. To this it may be replied, that soon after the
publication of the first volume (in 1810), I began to prepare
materials, and to institute experiments, relating to the oxides,
&c, with occasional diversions into other departments of
chemistry, as circumstances arose. As a great portion of my
time was always necessarily engaged in professional duties,
and as that part of the work I was about to commence was
one running into detail, I thought it would be best to print it
as I proceeded, whilst the train of thought and of experiments
was fresh in view. The advantage in this case was expected
to be partly at least counterbalanced by the loss of discoveries
and improvements likely to be made in the interval between
the printing and publishing of the several articles. This I
was aware of; but as a principal object I had in view was to
VI. TREFACE.
give the results of my own experience, in the various depart-
ments of chemical science, rather than to form the best com-
pilation of Chemistry at the period, this object was most
likely to be obtained by the proposed plan. It is true the
time the work has been in the press has far exceeded my ex-
pectation; notwithstanding this I am not conscious of any
very material alterations or additions, which I should wish to
make at the present moment.
It affords me great pleasure to acknowledge the assist-
ance I have had during the progress of this volume, from a
valuable selection of chemical apparatus, for which I am
indebted to the generosity of Mr. Sharpe; also the continued
and friendly intercourse with Dr. Henry, whose discussions
on scientific subjects are always instructive, and whose stores
are always open when the promotion of science is the object.
My present design is to add a second part to this volume,
and with that to finish the work. It will eonsist of the more
complex compounds. Acids, and other products of the ve-
getable kingdom, Salts, &c, will form principal parts.
Already I have a stock of experiments on these subjects;
but I am not satisfied without exploring this region afresh,
August, 1827. *-*®*
CONTENTS OF VOL. II.
Part First.
Page,
Chap. v. — compounds of two elements.
Section 13. Metallic Oxides.... 1
Oxide of Gold 5
•J Platina H
. : Silver • ••• 17
Oxides of Mercury 1*
Oxide of Palladium 24
Oxides of Rhodium, Iridium, and
Osmium. ... • 26
Copper * 26
Iron 28
Nickel 34
Tin 36
Lead 39
Oxide of Zinc .. «*i
Oxides of Potassium 53
Sodium , 56
Oxide of Bismuth 57
Oxides of Antimony 58
Oxide of Tellurium 62
Oxides of Arsenic 63
Cobalt 68
Manganese * 7i
. Chromium 80
— — — Uranium 86
— Molybdenum 87
Tungsten 90
. Titanium. 91
Columbium 92
Cerium 94
X. CONTENTS.
Pa©?
Section 14, Earthy, Alkaline, and Metallic SuL
pliurcts 96
Siifphurets of Li?nc 99
Sulphuret of Magnesia Ill
Sulphurcts of Barytes 112
Stroniitcs 114
Alumine, Si lex, Yitria,
Glucine etncl Zireonc ... 114
._ — Potash :..;.; 116
■ ■-■ — Sbda..... 119
Sulphuret of Ammonia 120
Sulphurots of Gold...,, ,. 121
Sulphuret of Platina. 123
Sulphurets of Silver 126
"• — Mercury 127
Sulphuret of Palladium 131
- — / ' Rhodium 132
'•'""" ' '" " Iridium 132
- - lll ■- — Osmium 132
- Sulphurets of Copper ... 133
* — — - — — — Iron 134
' Nickel 138
— — —Tin 139
— Jbead. 144
— — Zinc 146
► Potassium and Sodium ... 148
Bismuth 149
Antimony 151
Sulphuret of Tellurium 153
Sulphurets of Arsenic 153
Sulphuret of Cobalt , 160
Sulphurcts of Manganese 162
Sulphuret of Chromium 163
Uranium 164
-r — Molybdenum 164
Sulphuret of Tungsten 1 64
CONTENTS XI.
Page.
Sulphur cts of Titanium, Columbium, and Cerium .... 165
Section 15. Earthy, Alkaline, and Metallic Phos-
phurets 1 66
PJwsphurct of Hydrogen 169
Phosphurets of Carbon and Sulphur 184
Phosphuret of Lime.... 184
. Barytcs ._ 188
Strontites ............. 190
Gold 191
— — Platina 194
_ , Silver 195
1 Mercury 197.
Palladium 198
Copper.. 199
— Iron ... 201
Nickel , 201
— Tin ....s 202
— - Lead 203
Phosphurets of Zinc and Potassium ...... 204
Sodium and Bismuth ....... 207
— Antimony and Arsenic ..'.• 208
Phosphuret of Cobalt % 209
Manganese * 210
Section 16. Carburets.... 211
._ of Iron... steel 212—214
Section 17. Metallic Alloys 218
Alloys of Gold, with other metals.... 222
Platina, with other metals 226
— Silver, with other metals... 228
Mercury, and other metals .
amalgams 230
Triple, Quadruple, fyc. amalgams ... 236
Alloys of Copper, with other metals 238
Iron, with other metals ... 253
Alloys of Nickel and Tin, with do.. t, 254
Lead, ivith do. 258
Xll. CONTENTS.
Section 17. Triple Alloys, Solders ; fusible metal, dfc. 203
APPENDIX.
Abstract of De hi Roche and Bcrard's essay on the
specific heat of gases 268
Du yong and Pctitfs essays,
On the expansion of air, mercury, glass, iron,
copper, and plettina, by heat 272
On the capacities of certain bodies, for heat 274
On the laics of refrigeration *...., 277
On the specific heats of certain bodies 280
Remarks on the above essays 282
New Table of the forces of vapours 298
Table of the expansion of air, and the force of aqueous
and tethcrial vapour, adapted to atmospheric
temperatures. 299
Applications of the eibove table 300
Formulae for determining the proportions of combustible
gases, in mixtures 305
Heat produced by the combustion of gases 309
Absorption of gases by water 309
Fluoric acid — deutoxide of hydrogen 311
Muriatic acid — oxy muriatic acid 313
Nitric acid — compounds of azote and oxygen 315
On ammonia., 328
Decomposition of ammonia by nitrous oxide 330
by nitrous gas and oxygen 332
Volume of gases from the decomposition of ammonia,,, 335
Decomposition of ammonia by a red heed 335
Decomposition of ammonia by oxymuriatic acid 335
Sulphuret of Carbon 338
Potassium, Sodium, Sfc ;».. 340
Alum 311
New table of the relative weigh ts of atoms 352
Addenda. Steel ; mixed gases ; expansion of liquids
bu heat ,, .» 354
NEW SYSTEM
OF
CHEMICAL PHILOSOPHY.
CHAP. V.
SECTION 13.
METALLIC OXIDES.
^A-LL the metals are disposed to combine
with oxygen, but the combination is effected
more easily with some than with others; the
compound is usually called an oxide, but in
some instances it is also called an acid. The
same metal combines with one, two, or per-
haps more atoms of oxygen, forming com-
pounds which may be distinguished accord-
ing to Dr. Thomson, by the terms protoxide,
deutoxide, trit oxide, . &c.
Such however is the repulsion of oxygen to
oxygen that we rarely find three atoms of it
retained by a single atom of any kind ; and
there are not many instances of metals capa-
VOL. II. A
2 METALLIC OXIDES.
ble of holding two atoms of oxygen. Vari-
ous modifications of the proportions of metals
and oxygen arise from the combinations of
the oxides themselves one with another and
with oxygen, so as to lead some to imagine
that an atom of metal in some instances com-
bines with 3, 4, or more of oxygen. This
is altogether improbable: It is much more
simple to suppose that one atom of oxygen
connects two or more atoms of protoxide,
1 of protoxide unites to 1 or more of deut-
oxide, &c. These intermediate oxides are
in few if any instances found to combine
with acids like the other two oxides.
There is no reason that I am acquainted
with for disbelieving that oxygen combined
with a metal is still repulsive df oxygen,
and that by the same law as particles of an
elastic fluid; that is, the repulsion is inversely
as the distance of the centres of the atoms.
Hence it may be demonstrated that it re-
quires twice the strength of affinity to form
a deutoxide as a protoxide* three times the
strength to form a tritoxide as a protox-
ide> Sec; On this account it is, in all proba-
bility, that deutoxides are not numerous, and
tritoxides are rarely if ever found.
The quantity • of oxygen that combines
METALLIC OXIDES. 3
with any metal to form an oxide may be in-
vestigated by several methods.
1st. By combustion; a given weight of
the metal may be burned and the oxide pro-
duced may be collected and weighed ; when
the increase by combustion will appear.
2. By solution in an acid and precipitation
by an earth or alkali; in this case a given
weight of the metal is dissolved and precipi-
tated; the precipitate collected and suffici-
ently dried shews the increase by oxygen.
3. By transferring the oxygen from an
oxide to another metal; in this case the me-
tal in question is usually immersed in a saline
solution of the other metal; this latter me^
tal gives up its oxygen to the former and is
itself reformed or revived as it is termed.
4. By determining the proportion of hy-
drogen gas evolved during the solution of a
given weight of metal; then allowing half of
that volume for its equivalent of oxygenous
gas, the weight of it shews the oxygen united
to the metal; it being now well understood
that water furnishes the two elements of hy-
drogen and oxygen in such case.
5. The higher oxides are conveniently de-
termined by the application of the solution
of oxymuriate of lime to the lower oxides in.
solution.
4 METALLIC OXIDES.
6. The quantity of oxygen in several ox-
ides may be found from the quantity of ni-
trous gas evolved during the solution of a
given weight of metal in nitric acid.
The first four methods have been used by
chemists for several years past; the two last
1 have added from my own experience, hav-
ing found them very useful assistants in vari-
ous instances. The last method by nitrous
gas, has indeed been proposed before, and la-
bour bestowed on it both by others and my-
self, but without reducing the results to any
certainty, till lately ; the principal cause of
this want of success has arisen from misunder-
standing the nature and constitution of nitric
acid. Most chemists seem with me to have
mistaken nitrous acid for nitric ; the former
is composed of 1 atom of azote and 2 of
oxygen ; or perhaps of 2 azote and 4 oxygen ;
the latter of 2 azote and 5 oxygen, or 2 nitrous
gas and 3 oxygen ; the weight of the former
is* 19, or its double 38, on my scale, and that of
the latter 45. [My reasons for adopting the
above conclusion respecting nitrous acid,
which is at variance with that in Vol. 1,
p. 331, will be given hereafter.] When there-
fore a metal is oxidized by nitric acid, 3
atoms of oxygen (= 21) go to the metal, and
2 atoms of nitrous gas (= 24) are disengaged.
METALLIC OXIDES. 5
Hence \ of the weight of nitrons gas evolv-
ed is the weight of oxygen combined. It
sometimes happens however that the nitrous
gas is partly or wholly retained by the residue
of nitric acid ; but in this case the oxy muriate
of lime can be applied to convert the nitrous
gas into nitric acid, and from the oxygen im-
bibed the quantity of nitrous gas may be in-
ferred.
1. Oxide of Gold.
Some difficulties have been found in ascer-
taining both the number and proportions of
the oxides of gold; hence the differences in
the results of authors.
Gold does not burn by exposure to heat,
but gold leaf and gold wire may be deflagra-
ted by electricity and galvanism ; a purple
powder is the product, which is considered
by some as the protoxide of gold ; but others,
after Macquer and Proust, conceive with
greater probability that this powder is no-
thing but gold reduced to its ultimate divi-
sion. Solutions of gold which are of a fine
yellow, give a purple stain ; and gold deoxi-
dized by green sulphate of iron is precipita-
ted blue, which precipitate gradually as-
sumes a yellow colour as the particles become
6 METALLIC OXIDES.
united. The very weak affinity of gold for
oxygen is shewn by the difficulty with which
it is oxidized and the ease with which the
oxygen is expelled again by heat; these
facts seem to preclude the idea of gold com-
bining with oxygen in high temperatures.
Protoxide. Gold is scarcely affected by
pure sulphuric, nitric or muriatic acid; but
it is easily oxidized and dissolved by nitro-
muriatic acid (that is, a mixture of nitric
and muriatic acids) when assisted by a tem-
perature of 150 or 200°. Caustic potash be-
ing put into the solution and heated, a brown-
ish black precipitate is obtained; but a part
of the oxide remains in solution combined
with the muriate of potash, according to
Vauquelin ; and Proust has observed that the
oxide cannot be washed and dried in a mode-
rate heat without a portion of the gold being
revived; hence the difficulty of ascertain-
ing in this way the weight of oxygen com-
bining with gold.
I have succeeded, as I apprehend, in de-
termining the relative weights of gold and
oxygen, by two methods, which mutually
corroborate each other. The first is by
means of th# nitrous gas generated by the
solution of gold ; and the second is,* by find-
ing what quantity of green oxide of iron is
METALLIC OXIDES. 7
converted into red by precipitating a given
weight of gold in solution.
Ten grains of guinea gold of the sp. gr.
17.3, were repeatedly dissolved in a small
excess of nitro-muriatic acid; the quantity
and purity of the nitrous gas generated were
duly observed and allowance made for the loss
occasioned by a small portion of common air
originally in the gas bottle. The volume of
nitrous gas corrected as above was always
found between 1100 and 1200 grain measures,
the weight of which may be estimated at J .6
grains, corresponding to 1.4 grains of oxygen.
The small portion of alloy (XV) known to be
in standard gold is chiefly copper with a small
part silver; now it will be seen in the sequel
that copper takes ~ of its weight of oxygen ;
hence if we allow .8 of a grain for copper
and .2 for the oxygen combining with it, we
shall have 9.2 gold united to 1.2 oxygen, or
100 gold with 13 oxygen, which is nearly the
same as Berzelius has determined by precipi-
tating the gold by mercury.— Again, 10
grains of gold were dissolved as above (= 9.2
pure) and precipitated by a solution of pure
green sulphate of iron of the sp. gr. 1.181
and which I had previously proved to contain
9 grains of green oxide in 100 measures.
They converted 120 measures of this green
8 METALLIC OXIDES*
sulphate into yellow, which was carefully
precipitated afterwards by lime water, dried
and weighed. The gold precipitated was
found very nearly 9 grains; and the yellow
oxide of iron mixed with oxide of copper
was nearly 13 grains. Now 120 measures
sulphate iron contain 10.8 grains green oxide,
and these require ~ of their weight of oxy-
gen (see the oxides of iron) to be changed
into yellow oxide, or 1.2 oxygen. Hence it
appears that the oxygen combined with the
gold was transferred to the iron unchanged in
quantity. It is to be observed however that
green oxide of iron not only deoxidates the
gold but it semideoxidates the copper also ;
so that .1 of the transferred oxygen above
might be said to be derived from the copper,
and the rest, or 1.1 from the 9 grains of gold ;
this would give 100 gold to 12.2 oxygen,
which is still nearer to the determination of
Berzelius. Upon the whole I am inclined to
adopt the proportion of 8 to 1 or 100 to 12.5
as that which appears the most correct ap-
proximation and at the same time a ratio
easily remembered and adapted to facilitate
calculations.
We are now to consider whether the above
is the protoxide. As no other oxide has been
clearly shewn to exist, and as this combines
METALLIC OXIDES. 9
with muriatic acid, with ammonia, with
the oxide of tin, &c. and is wholly deoxi-
dated by green sulphate of iron and by a mo-
derate heat, there seems every reason to con-
clude it is a combination of the most simple
kind, or 1 atom of metal to 1 of oxygen.
Hence the atom of oxygen being 7, that of
gold must be 56, and not 140 or 200, as sta-
ted Vol. 1, p. 250.
Berzelius seems to consider the above as the
tritoxide, or three atoms of oxygen to one of
gold; but it is extremely improbable that
gold, which is allowed to have a weak affinity
for oxygen, should be able to restrain the
violent repulsion of three atoms of oxygen,
and should on every occasion lose them all at
once, and not by degrees, as is usual with
other high oxides.
Subjoined are the results of various au-
thors in regard to the oxide of gold, but ge-
nerally given with diffidence as to their ac-
curacy.
gold
oxygen
Bergman 100
+ 10
Proust
4- 8.57 to 31.
Oberkampf — —
+ io
Berzelius «
-f 12 (4, suboxide)
My results —
+ 12.5
roL. ii.
B
10 METALLIC OXIDES.
Since writing the above I have had an op-
portunity of repeating the experiments on
the oxide of gold by an improved nitrous gas
apparatus, calculated almost entirely to ex-
clude atmospheric air; I find less nitrous gas
produced during the solution than stated
above, sometimes by 4, and that it is variable
according to the excess of nitric acid ; also
that the solution requires a portion of oxymu-
riatic acid as an equivalent for the nitrous gas
retained. I prefer, however, the method of
oxidizing the green sulphate of iron; by
putting a small excess of the green sulphate
and precipitating, first the red oxide and then
the green, I obtained very distinct results.
On the whole I am inclined to think my re-
sults preceding these have rather overrated
the oxygen, and that it would as nearly be
stated at 11 on the hundred. This would be
nearly a mean of those in the above table,
and would require the atom of gold to be 63,
and that of the oxide 70. Between the two
extremes of 56 and 63 it is most probable the
true weight of the atom of gold will be
found.
It may be proper to add that I have found
100 grain measures of muriatic acid (1.16),
and 25 of nitric (1.35), are sufficient to dis-
solve 40 grains of standard gold; and I have
METALLIC OXIDES. 11
reason to think the acids are in due proportion
nearly, though different from what is usually
recommended and employed.
2. Oxide of Platina.
Platina exhibits greater difficulties than
gold in the investigation of its compounds
with oxygen. It is not oxidized by heat;
but by the explosion of an electric battery it
is converted into a black powder, which is
most probably the metal in extreme division,
though it has been considered by some as the
protoxide. Platina is capable of being oxi-
dized and dissolved by nitro-muriatic acid,
but less easily than gold; it requires more
acid, as high or higher temperature and long
continued digestion; nitrous gas is given out,
during the solution, but sparingly. When
lime or an alkali is added to the solution
with a view to precipitate the oxide, a tri-
ple compound is usually formed of the acid,
the oxide and the alkali, which is in most
instances precipitated. This weighty com-
pound renders the valuation of the oxygen in
it very uncertain.
Chenevix has made some observations on
the oxides of platina, (see Nichols. Journ.
7. p. 178.) He finds two oxides: the one con-
12 METALLIC OXIDES.
sists of 93 platina and 7 oxygen; the other
of 87 platina and 13 oxygen; but the expe-
riments on which these results rest are not
quite satisfactory.
Mr. E. Davy in the 40th vol. of the Philos.
Magazine, states his having reduced the
oxide of platina in solution by means of hy-
drogen ; and that he finds the oxide to consist
of 84 platina and 16 oxygen nearly. I could
not succeed at all in effecting the reduction of
the metal in this way.
Berzelius has lately given us the results of
his investigation on this subject. (An. de Chi-
mie 87-. — 126.) According to this distinguished
chemist there are two oxides of platina; the
first consists of 100 metal and 8 J oxygen,
and the second of 100 metal and 16| oxygen*
nearly. In order to understand his process it
may be proper to premise that when nitro-mu-
riatic acid has dissolved as much platina as it
can, there is still a great excess of one or
both of the acids, which is unnecessary for
the existence of the solution, and which
may, and in general ought to be expelled by
evaporation; by exposing the solution to a
heat of 100 or 150° the excess of both acids
is in great part driven off and a dry red mass
is obtained, without smell, but very deliques-
cent. It is equal to or rather more than twice
METALLIC OXIDES. 13
the weight of the platina. It consists of wa-
ter, muriatic and nitric acids, oxygen and pla-
tina; it is still an acid salt. By exposing the
dry mass again to a heat of 400 or 500°, it
liquifies, exhales acid fumes having the odour
of oxymuriatic acid, and becomes again a
dry mass of an olive colour, exhaling fumes as
the heat increases, and loses about J of its
weight. It is still soluble in water, except a
few atoms of black powder, continues acid
to the tests, and may be considered as a su-
permuriate of platina. If this olive powder
be again heated almost to red, it exhales a vi-
sible smoke in the open air, which has the
smell of oxymuriatic acid, and becomes a
light brown powder, having lost a little
weight. It is then neither deliquescent nor
soluble in water except in a small degree so
as to give the yellow colour. In this state it
has been considered as a neutral muriate.
By a moderately bright red heat this powder
is decomposed and leaves a black spongy
mass which is found to be pure platina.
The insoluble muriate of platina according
to Mr. E. Davy, contains 72.5 per cent, of
platina, and Berzelius finds 73. 3j the loss is
considered as oxymuriatic acid ; hence from
the known proportions of this acid Berzelius
infers the constituents of 100 muriate=73.3
14 METALLIC OXIDES.
platina, 6.075 oxygen and 20.625 muriatic
acid ; or 100 platina take 8.3 oxygen. The
near agreement of the above authors is favour-
able to the accuracy of their results; but I
have found some difficulty in obtaining the
insoluble muriate free from the soluble one,
and at the same time from reduced platina
because the precise degree of heat requisite
to produce it is neither well known nor easily
attained; and it is desirable that a certain
weight of platina should be dissolved and the
same weight reproduced as a confirmation
of accuracy. From a train of experiments
on the soluble and insoluble muriates of pla-
tina, the salts being obtained from the puri-
fied laminated metal, I am disposed to consi-
der the above results as good approximations
to the truth.
In order to obtain the other oxide, Berze-
lius digests mercury in a solution of the super-
muriate of platina; a black powder is thrown
down, which is found to be platina, and mer-
cury is taken up, being oxidized at the expence
of the platina. It was found that 16.7 grains
of mercury had precipitated 8.5 of platina;
and the mercury being calculated as in the
state of deutoxide, contained, from the known
proportions of this metal, 1.4 oxygen; hence
8.5 platina must have yielded 1.4 oxygen;
METALLIC OXIDES. 15
and if 8.5:1.4:: 100:16.4; so that 100 platina
must have had 16.4 oxygen in the supermuri-
ate, or twice the quantity it had in the inso-
luble muriate.
This conclusion appears to me premature;
the mercurial oxide should at least have been
precipitated and a corresponding quantity
have been found and proved to be the red
oxide. Even had this been the case, it is not
easy to determine what quantity of it might
be due to the residue of nitro-muriatic acid.
But I have not found that the common yellow
or red oxide of mercury is precipitated by
lime water in such case; the precipitate is
brown, and evidently contains both mercury
and platina. Proust had found in his excel-
lent essay on platina (Journ. de Physique
52 — 437, 1801) that mercury decomposes mu-
riate of platina, that an amalgam of platina
with a little calomel, and much mercury in
powder, were precipitated ; exposed to heat,
a fine black powder was left which had the
characters of platina. Into a solution of
pure platina that had been evaporated to dry-
ness in 150° and redissolved, I put 9 J grs. of
mercury, and boiled it for 10 minutes in a glass
capsule, till there was apparently no further
change; the liquor filtered was as yellow as
at first; the mixture of black powder and
16 METALLIC OXIDES.
running mercury remaining"' on the filter,
when dried, weighed 6| grains; this heated
to a low red in an iron spoon, left 1 grain of
fine black powder; the liquid saturated with
lime water, yielded 2| grains dry black pow-
der insoluble in cold nitric acid; after this, pro-
tomuriate of tin threw down 5| grains of the
compound oxides of platina and tin. The so-
lution at first contained 3.3 grains of platina.
In another experiment 2 parts of calomel
were put to 1 of platina in solution; when
heated to boiling, the calomel was dissolved
and a little black powder was precipitated,
which did not amount to half the weight of
the platina. Lime water threw down from
the liquid, a yellowish olive or brown pre-
cipitate, partially soluble in cold nitro-muri-
atic acid; and after this, muriate of tin yielded
a brown precipitate. These experiments
shew that the action between muriate of pla-
tina and mercury or the mercurial salts, is
of a complicated nature, and is not limited
to the decomposition of the oxide of platina
and the substitution of the deutoxide of mer-
cury in its place.
The difficulties abovementioned have led
me to investigate the oxygen combining with
platina by means of the nitrous gas yielded
upon its solution in nitro-muriatic acid. By
METALLIC OXIDES. 17
three distinct experiments I found that 30
grains of pure platina by solution yielded
nearly 750 grain measures of nitrous gas,
which may be considered as 1 grain in weight ;
| of which = .875 for oxygen; this would
give 8.75 oxygen per cent. But from a sub-
sequent experiment made under circumstan-
ces calculated to preclude as much as possible
every source of fallacy, I obtained 790 mea-
sures of nitrous gas from 10 grains of pla-
tina; and the solution afterwards took 60
measures of oxy muriatic acid gas before a
permanent smell of the gas was produced.
These 790 measures = 1.05 grain, \ of which
= .92, to which add .04 for the oxygen acqui-
red from the oxymuriatic acid, and we have
,96 oxygen for 10 platina ; or 100 platina take
9.6 oxygen. But if 9.6 : 100 :: 7 : 73, for the
weight of an atom of platina, and 80 for
that of the protoxide, as I apprehend it to be,
and the only oxide of platina we can at pre-
sent form. (The atom of platina in Vol. 1,
page 248, was estimated at 100.)
3. Oxide of Silver,
When silver wire is exploded by electricity
in oxygen gas, a black powder is produced,
which is the oxide of silver. If silver be dis-
VOL. II. C
18 METALLIC OXIDES.
solved in nitric acid and precipitated by lime
water, an olive brown powder falls which be-
comes black when exposed to the light. This
-black powder is the only oxide of silver with
which we are acquainted. The proportion of
silver and oxygen has been investigated bj
various chemists; the results are as under.
silver oxygeu
Wenzel 100 4- s 8.5
Proust + 9.5
Bucholz and Rose ... 4- 9.5*
Gay Lussac. 4* 7.6 f
Berzelius , 4- 7.925
From the solution of 170 grains of standard
silver T obtained nearly 30 oz. measures of ni-
trous gas = 18| grains, corresponding to 16
oxygen. This would give 9.4 oxygen upon
1Q0 silver. But as TV of the metal or 17
grains was copper, and this takes -J. of its
weight of oxygen, we shall have 159 silver
and 1LJ oxygen, or 100 silver and 7.7 oxygen
nearly.
If we adopt 7.8 as the proper quantity of
oxygen on 100 silver, we shall have 7.8:
100 :: 7 : 90 nearly, which represents the
weight of an atom of silver, and 97 that of
the oxide.
* 7.9 when duly corrected. Annal. de Chimie, 78—114.
t Memoirs d'Arcueil 2—168.
METALLIC OXIDES. 19
4. Oxides of Mercury.
Two oxides of mercury have been long
known and are well distinguished from each
other. They may be obtained by exposing
mercury to a heat not exceeding 600% in con-
tact with oxygen gas or atmospheric air, and
due agitation ; but this method is rarely adop-
ted in practice. A high degree of heat de-
composes the oxides again.
Protoxide. To obtain the protoxide, mer-
cury must be slowly dissolved in dilute nitric
acid without heat, and an excess of mercury
must be used. If to 1000 grain measures of
nitric acid, 1.2 sp.gr. be put 500 grains of
mercury, by occasional agitation the requi-
site solution will be obtained in 24 hours.
A portion of this solution must be treated with
a small excess of lime water or caustic alkali,
when a black powder will be thrown down,
which is the oxide containing a minimum of
oxygen, and hence may be considered the
protoxide.
Deutoxide. If to 1000 measures of nitric
acid, 1.2 sp. gr. be put 350 grains of mercury,
and the mixture be boiled till the mercury dis-
appear, a solution will be obtained contain-
ing the deutoxide. A portion of this being
treated as beforementioned with lime water,
a yellowish red powder is precipitated, whicn
20 METALLIC OXIDES.
is the oxide of mercury containing a maxi-
mum of oxygen; all the later authors agree
that it contains just double the quantity of
oxygen to a given portion of mercury that
the former does, and may therefore be called
the deutoxide.
These two oxides combine with most acids
and form salts, some of which exhibit re-
markable differences occasioned by the ox-
ides; thus, muriatic acid with the protoxide
forms protomuriate of mercury, commonly
called calomel, an insoluble salt; with the
deutoxide it forms deutomuriate of mercury,
commonly called corrosive sublimate, a solu-
ble salt.
The proportions of metal and oxygen in the
two oxides may be found by precipitating a
known weight of mercury reduced by solu-
tion to either of the oxides, then drying and
weighing the oxides, when the increase of
weight by the addition of oxygen may be ob-
served. This method is less accurate with re-
gard to mercury than to other metals, on ac-
count of the very great weight of the atom,
by which a small error in the gross weight of
the oxide will be a great one as it respects
the oxygen. This circumstance will partly
account for the differences of authors on this
subject.
METALLIC OXIDES. 21
One fact has been for some time known
which demonstrates the oxygen in the red
oxide to be double that in the black. Cor-
rosive sublimate may be reduced to calomel
by adding to it as much mercury as the sub-
limate contains, and triturating the mixture
well, the oxygen of the red oxide (as well
as the acid) becomes equally divided amongst
the mercury and forms the black oxide, which
is a constituent of calomel. Hence it fol-
lows that if the oxygen in one oxide can be
ascertained, that of the other becomes known.
Or if we can find how much oxygen must be
added to the black oxide to change it to the
red, we shall know the oxygen in both.
Conformably with this last idea I have found
a very accurate and elegant method of ascer-
taining the oxygen required to convert the
black to the red oxide by treating protomu-
riate of mercury, mixed with water and a lit-
tle muriatic acid, with oxymuriate of lime
in solution; this must be gradually added till
the protomuriate is dissolved,- or rather con-
verted to the deutomuriate. The quantity of
oxygen in a given solution of oxymuriate of
lime is most conveniently found by a solution
of green sulphate of iron, : as will be shewn
under the' oxides of that metal.
The oxides of mercury may be investigat-
22 METALLIC OXIDES.
ed by the nitrous gas produced during solution.
When mercury is dissolved without heat, as
mentioned above, no nitrous gas is liberated.
The solution has a strong nitrous smell and
requires a great quantity of oxy muriate of
lime to saturate both the oxide and the acid.
When heat is employed to accelerate the so-
lution, nitrous gas is liberated. I dissolved
154 grains of mercury, in nitric acid, 1.2
sp. gr., by the application of a gentle heat
from a lamp. About ^ excess of acid re*
mained in the solution; the nitrous gas ob-
tained was 12 oz. measures =7.5 grains, cor-
responding to 6.5 oxygen, which gives nearly
4 oxygen or 100 mercury. This would have
led me to suppose I had obtained the black ox-
ide in solution ; it was however entirely the
red, as it gave no precipitate by common salt,
and exhibited the red oxide by lime water;
but it required as much oxymuriate of lime as
contained 6.5 oxygen to saturate the nitrous
gas in the solution before any oxymuriatic acid
was liberated. It was clear therefore that
only | of the nitrous gas was evolved, and
the other § was retained in the solution,
though it had been exposed to boiling heat.
The following are the proportions assigned
by the several authors for the oxides of
mercury.
METALLIC OXIDES. 23
Mercury. Oxygen.
^ %
black. red.
Bergman* 100 + 4 +
Lavoisierf H •jr 7.75 to 8
Chenevixj — - +12 + 18.5
Taboada|| + 5.2 + 11
Fourcroy & Thenard (a) + 4.16+ 8.21
Sefstrom (6) + 3.99 + 7.99
My results give + 4.2 + 8.4
Though the relative weights of oxygen and
mercury may be investigated as above, yet it
is from the weight of mercury and the acids
in the salts of mercury, some of which are of
a very definite character, such as the muri-
ate and the deutomuriate, that the relative
weight of the atom of mercury is best inves-
tigated. From these I first deduced the
weight of an atom of mercury to be 167
about 10 years ago, and subsequent experi-
ence has not induced me to change the num-
ber, though it probably may admit of some
correction. If the atom of mercury be deno-
ted by 167, that of the protoxide will be 174,
* Kirwan's Mineralogy.
t Annals of Philosophy, Vol. 3, p. 333.
1 Philos. Trans. 1802.
|j Jour, de Physique. 1805.
(a) Mem.d'Arcueil,Vol.2.p.l68. 1809.
(b) Annals of Philosophy, Vol.2, p. 48.
24 METALLIC OXIDES.
and that of the deutoxide 181 ; which makes
100 mercury take 4.2 and 8.4 oxygen for the
oxides respectively, as in the above table.
5. Oxide of Palladium.
The discoverer of this metal, Dr. Wollas-
ton, has given us its distinguishing chemical
properties ; but we are indebted to Berzelius
and Yauquelin for the proportions of oxygen
and sulphur which combine with the metal
(Vid. Annal. de Chimie, 77 arid 78.) Few
chemists have had an opportunity of making
experiments on this metal, owing to its great
scarcity and the consequent high price of it
(1 shilling per grain). It does not seem de-
sireable that any but those skilled in the more
delicate chemical manipulations should ope-
rate upon articles such as the present.
Berzelius treated the muriate of palladium
with mercury, which abstracted the oxygen
and left an amalgam of palladium and mer-
cury ; from the quantity of mercury dissolved
he calculates that 100 palladium combine
with 14.2 oxygen. This conclusion was cor-
roborated by the circumstance that 100 palla-
dium were found to take 28 of sulphur, or
double the quantity of oxygen, which fre-
quently happens with the metals.
METALLIC OXIDES. 25
Vauquelin precipitates the oxide of palla-
dium from the muriate by potash; it appears
of a red brown colour, and is probably a hy-
drate ; when washed and dried in a moderate
heat, it becomes black, it loses 20 per cent,
by a red heat and becomes metallic. This
would give 25 oxygen on 100 metal ; but as
he finds the sulphuret to be 100 metal with 24
or 30 sulphur, nearly agreeing with Berze-
lius, it is very probable that a moderate heat
does not free the oxide from water, and that
consequently a part of the 20 per cent, loss
is water.
I dissolved 3 grains of palladium in a small
excess of nitro-muriatic acid and obtained
240 grain measures of nitrous gas ; the same
quantity was obtained a second time, and to
the solution (slightly acid) were added by de-
grees 200 measures of oxymuriatic acid gas;
after agitation no smell was perceived, but
by increasing the quantity of gas a perma-
nent smell of oxymuriatic acid was produ-
ced, and when 200 more had been added the
smell was sensible for some days in an open
jar, a presumption that no higher oxide is to
be obtained. Now 240 nitrous gas = .32 of
a grain, corresponding to .28 of oxygen, and
200 oxymuriatic acid = .64 of a grain, cor-
VOL. II. D
26 METALLIC OXIDES.
responding1 to .15 oxygen; the sum of the
two portions of oxygen = .43, which must
have combined with 3 grains of palladium ;
if .43 : 4 : : 7 : 50 nearly. Or 100 metal com-
bine with 14 oxygen, as determined by Ber-
zelius. I find the sulphuret to accord with
this determination; and by carefully satura-
ting the excess of acid in the nitro-muriate
of palladium and then finding the quantity of
lime-water necessary to precipitate a certain
weight of palladium, as well as the quantity
of test muriatic acid necessary to dissolve the
precipitated oxide, I am confirmed in the
opinion that the atom of palladium must
weigh 50 nearly, and its oxide 57, which
there is every reason to believe is the prot-
oxide.
6, 7, and 8. Oxides of Rhodium, Iridium,
and Osmium.
Nothing certain has yet been determined
respecting the oxygenation of these very
rare metals.
9. Oxides of Copper.
There are two oxides of copper according
to the results of Proust, Chenevix, Berze-
lius and others, the proportions of which are
METALLIC OXIDES. 27
given nearly the same by all, and so as to leave
no reasonable doubt concerning their accu-
racy.
1. Protoxide. This oxide is orange, and
contains 12| oxygen on 100 copper: it is ob-
tained by precipitating a portion of copper
from the solution of any cupreous salt, by
means of iron, then mixing this copper with
a rather greater portion of the deutoxide and
triturating them well. This being done, the
mixture is to be dissolved in muriatic acid,
and the orange oxide may then be precipita-
ted by an alkali.
2. Deutoxide. This oxide is black ; it con-
tains 25 oxygen on 100 copper : the black
oxide is obtained by dissolving copper in ni-
tric or sulphuric acid, then precipitating by
lime-water or an alkali, and heating the dried
precipitate red hot. It may also be obtained
by exposing copper to a red heat for some
time in common air or oxygen gas, removing
the scales and exposing them in like manner,
till at length the black oxide is formed.
By dissolving 112 grains of copper turn-
ings in 1000 grain measures of 1.16 nitric acid,
1 obtained 48 oz. measures of nitrous gas,
= 30 grains ; by oxy muriate of lime I found
2 grains of nitrous gas in the solution, mak-
ing in all 32 grains = 28 grains qf oxygen,
28 METALLIC OXIDES.
Tf 28 : 112 :: 14:56, for the weight of an atom
of copper; hence the protoxide — 63 and the
deutoxide = 70. These weights I adopted in
1806, and have not seen any reason to modify
them since.
10. Oxides of Iron,
Two well known and well distinguished
oxides of iron are now universally admitted ;
the one contains 28 oxygen on 100 iron, the
other 42 on 100.
1. Protoxide. This is always formed when
iron is dissolved in dilute sulphuric or muriatic
acid ; it may be precipitated from these solu-
tions by the pure alkalies or earths ] it appears
at first of a dark green, being then a hydrate
or combined with water; on a filtre it soon
becomes yellow at the surface by attracting
oxygen ; when dried in a heat of 200° or up-
wards it becomes black. The quantity of
oxygen in it is best ascertained from the hy-
drogen generated during the solution of the
iron. All the authorities I have found nearly
concur in their results as under.
100 grains of iron dissolved in dilute sul-
phuric or muriatic acids yield hydrogen, ac-
cording to
METALLIC OXIDES. 29
Cavendish (1766) 155 cubic inches.
Priestley, from 147 to 162
Lavoisier 163
Vandermonde, Berthollet, | max 176
and Monge y
Vauquelin 160 to 179
Dr.Thomson 163
My own Experiments give 160
Mean 164=82 oxygen^
27.9 grains.
By precipitating the oxide, and drying it,
nearly the same result may be obtained, as
100 iron will yield 128 oxide. This oxide is
magnetic.
2. Intermediate or red oxide. This oxide
may be obtained in various ways. First by
calcining the sulphate or nitrate of iron.
Second by precipitation from old solutions
of the salts of iron ; the precipitate is yellow
at first, being perhaps a hydrate; but when
dried and heated it becomes brown-red.
Third, by calcining iron or repeatedly expos-
ing iron filings to a red heat, and tritura-
tion. Fourth, by treating a solution of the
sulphate or other salt of the protoxide with
oxmuriatic acid, or oxymuriate of lime till
t^xy muriatic acid is evolved; then precipitat-
ing-the oxide which is thus converted into the
red. Fifth, by agitating water containing the
30 METALLIC OXIDES.
green oxide recently precipitated, with oxy-
gen gas. The red oxide is not sensibly mag-
netic.
The quantity of oxygen in the red oxide
may be investigated in various ways, and it
is generally allowed that they all concur in
giving 42 on 100 iron. The one which I
have used peculiarly, and prefer both for ease
and accuracy, is to find the quantity of oxy-
muriatic acid gas necessary to saturate a given
portion of the green sulphate. I take for in-
stance 100 measures of 1.149 green sulphate,
which I know to contain 8 grains of black
oxide ; this I find absorbs nearly 13 hundred
measures of oxymuriatic acid gas before the
acid smell is developed ; the oxygen cor-
responding to this quantity of acid is known
to be near 660 measures, = .88 grain. (See
Vol. 1, p. 308.) Hence, if 8: .88:: 128 : 14;
or 128 black oxide acquire 14 or become 142
when converted into the red oxide. This
fact being established, I find it very conve-
nient to make use of the oxymuriate of lime
instead of the acid gas, adopting the solution
of green sulphate of iron as a test of the
quantity of oxymuriatic acid in a given vo*
lume of any solution of oxymuriate of lime.
The quantity of oxygen in the red oxide of
METALLIC OXIDES. 31
iron may be inferred, but not so satisfacto-
rily, from the nitrous gas obtained during the
solution of iron in nitric acid. In order to
obtain the most gas from a given quantity of
the materials, they should be so proportioned
as to produce saturation nearly. If an excess
of acid be used, it absorbs the nitrous gas in
part; and if an excess of iron, it is not all
dissolved. I took 50 grains of iron filings
and 600 measures of 1.15 nitric acid; these
were put together in a gas bottle and by the
assistance of a little heat a quantity of ni-
trous gas was obtained equal to 12 grains in
weight, allowing the sp. gr. of the gas to be
1.04 (air being 1) ; all the iron was dissolved
except a few atoms, and the solution was
slightly acid ; the whole of the oxide was red
when precipitated by lime water. Now 50
grains of iron take 21 of oxygen to form the
red oxide, and these correspond to 24 of ni-
trous gas, which is just twice the quantity
obtained; one half of the gas generated then
remains in combination with the iron, even
when the constituents of the salt are pro-
portioned so as to produce mutual saturation.
I was in expectation that the quantity of ni-
trous gas retained might be converted into
nitric acid by oxymuriate of lime, and hence
might be determined; but in this I was dis-
32 METALLIC OXIDES.
appointed. When oxymuriate of lime is
added to the liquid, a pungent gas is libe-
rated, the nature of which I have not de-
termined. Thinking, it might in part be
owing to the iron, I transferred the acid
to soda, by decomposing the nitrate of iron
by the carbonate of soda ; this nitrate of
soda however, when treated with oxymu-
riate of lime, exhibited the same pheno-
menon as the nitrate of iron. When an
acid is added the oxymuriatic acid itself is
given out. These results will require further
consideration. At present I am inclined to
think the pungent gas is one atom of nitrous
and one of oxygen or what I formerly con-
sidered as nitric acid. (See Vol. 1, plate 4,
ng. 27.)
Some authors have found as they conceive,
other oxides of iron, containing less or more
of oxygen than the above ; thus Darso finds
by calcination from 15 to 56 oxygen on 100,
(Nicholson's Journ. Vol. 17); but there is
great reason to believe that uncertainties must
exist in his mode of experimenting sufficient
to account for the anomalies observed. This
author has suggested some doubt whether the
oxygenous gas naturally contained in water
has any effect on the salts with green oxide of
iron. I have ascertained that point by re-
METALLIC OXIDES. 33
peated experiments, and can assert that the
oxygen in water immediately unites to the
green oxide of iron to convert it into red, and
that the green sulphate may be used as an ac-
curate test of the quantity of oxygen in water.
When pure green sulphate of iroh is dropped
into water and then the oxide precipitated by
a gradual addition of lime water, it falls down
yellow in proportion to the oxygen in the wa-
ter, which may be increased 3 or 4 times
by artificial impregnation. If the oxygen of
the water be previously saturated with nitrous
gas, then the oxide is wholly precipitated
green.
Gay Lussac, in the 80th Vol. of the AnnaL
de Chimie, asserts that an oxide of iron con-
taining 37.8 oxygen upon 100 iron is always
obtained when iron is burned in oxygenous
gas, and still more effectually when iron is
oxydized by water or steam. If this oxide
exist in the proportions stated, it must be a
compound of 1 atom of the protoxide and 2
of the red oxide, which would give 37.3
oxygen on 100 of iron.
From the above facts and observations it is
evident the atom of iron must be considered
as weighing 25, (and not 50 as already given,
Vol. 1, page 258) ; the protoxide is 32, and
VOL. II, E
34 METALLIC OXIDES.
the intermediate or red oxide is 2 atoms prot-
oxide and 1 of oxygen = 71.
11. Oxides of Nickel.
1. Protoxide. It appears to be ascertained
from the experiments of Proust (Journ. de
Physiq.63— 442),Xtichter (Nichols .Jour.12.),
Tupputi (An. de Chimie 78.), and RolhofF
(An. of Philos. 3 — 335.), that the protoxide of
nickel consists of 100 metal and from 25 to 28
oxygen. My experiments on the solution of
nickel in nitric acid give me 14 grains ni-
trous gas, corresponding to 12 oxygen, in
the solution of 44 grains of nickel ; this
gives 100 nickel to 27 oxygen, which I adopt
as agreeing with the mean of the beforemen-
tioned results. This oxide may be obtained
by precipitation from a solution of nitrate of
nickel ; it is at first white, being then a hy-
drate ; when dried in a moderate temperature
it becomes yellowish; after this, being heated
to a cherry red, it loses from 20 to 24 per cent,
of water and becomes of an ash grey colour :
this is the only oxide of nickel soluble in
acids, and must therefore be deemed the prot-
oxide ; hence we have 27 : 100 :: 7 : 26, nearly,
METALLIC OXIDES. 35
for the weight of an atom of nickel; and
not 25 or 50, as estimated at page 258. Vol. I.
Intermediate oxide. Thenard discovered a
second oxide of nickel by passing oxymuri-
atic acid through a solution of nickel and then
precipitating; it is a black powder; when
treated with sulphuric or nitric acid it gives
out gas, being the excess of oxygen above
the protoxide ; but with muriatic acid it gives
oxymuriatic acid gas. RolhofF was induced
to believe, but I do not know upon what evi-
dence, that this oxide contained 1^- or If
times the oxygen of the protoxide. By
means of oxy muriate of lime I find the prot-
oxide recently precipitated, takes half as much
oxygen as it had previously, to form the black
oxide; and that it cannot be formed, like the
red oxide of iron, by agitation with water
mixed with common air. The white oxide
treated with oxymuriate of lime becomes al-
most instantly blue, growing darker till it
gradually passes into brown, and finally black
in about half an hour. It contains 40 oxygen
on 100 nickel, and is most probably consti-
tuted of 1 atom of oxygen holding 2 of
protoxide together, more especially as it is not
found in combination with acids. The me-
thod I prefer to procure the black oxide is to
precipitate a known weight of oxide by lime
36 . METALLIC OXIDES.
*
water ; then pouring off the clear liquid, I
put as much liquid oxymuriate of lime to the
moist hydrate as contains XV of the weight
of the oxide of oxygen, and stir frequently
for half an hour ; the point of saturation is
found when more oxide put to the clear liquid
is not discoloured on one hand, and when
more oxymuriate of lime does not affect the
colour, but remains in the clear liquid on the
other hand.
12. Oxides of Tin.
There are two .oxides of tin, which have
been carefully investigated by several che-
mists, and appear to be ascertained with great
precision. The protoxide is grey, and con-
tains 13| oxygen on 100 tin; the deutoxide
is white, and contains 27 oxygen on 100 tin.
1. Protoxide. There are t\v.o methods of
obtaining the constitution of this oxide. The
first is by dissolving a certain weight of tin
filings in muriatic acid, precipitating by lime
water or carbonated alkalies and drying the
oxide in a moderate heat ; this is liable to
some uncertainty ; the precipitate being a hy-
drate, requires to be exposed to heat to expel
the water ; but if the heat approaches to red,
the oxide takes fire and is converted into the
METALLIC OXIDES. 37
deutoxide. The second method is to dissolve
tin in muriatic acid and carefully collect the
hydrogen gas evolved; this was first done by
Mr. Cavendish, with his usual accuracy, and
published in 1766; he found 1 oz. of tin
yield 202 oz. measures of hydrogen gas. I
have frequently tried this experiment and al-
ways found a proportional quantity, or very
nearly 200 measures for each grain of tin.
This mode of investigation appears to me
unexceptionable. Now 200 hydrogen unite
to 100 oxygen, and 100 grain measures of
oxygen=.134 grain in weight; hence if .134
oxy. : 1 tin :: 7 oxy. : 52 nearly for the weight
of an atom of tin, on the presumption this
is the protoxide.
2. Deutoxide. This may be obtained by
heating tin till it takes fire, and the produce
of the combustion is the oxide required; but
to ascertain the proportions of tin and oxygen
two other methods are preferable ; the one is
to treat tin with nitric acid of the sp. gr.
1.2 to 1.4; a violent effervescence and great
heat ensue and the tin is converted into a
white powder. This being dried in 100* gives
about 160 grains for 100 of tin. It consists
of the deutoxide united to a little acid and
water; these two may be driven off by a low
red heat, and 127 grains of the deutoxide
38 METALLIC OXIDES.
remain in the state of a white powder. The
other method is to treat a solution of the prot-
oxide of tin with oxy muriate of lime till it
is saturated; this will be found when 59
grains of the protoxide have acquired 7 grains
of oxygen, or 1 13{ have acquired 1.3 J of oxy-
gen, which corroborates the result by the 1st
method. This oxide containing just twice as
much oxygen as the former, may justly be con-
sidered as the deutoxide. No higher oxide
of tin has been obtained.
The two oxides, though both white when
precipitated, may be distinguished from their
different appearances ; the first is curdy, the
second, gelatinous.
It may be proper to subjoin authorities for
these oxides:
Tin Protoxide Deutoxide
Cavendish, from the hydrogen 100 113.5
Proust (Journ.de Physique 59—341) 100 115 127^.128*
Gay Lussac (Annal. de Chimie 80—170) 100 113.5 127.2f
Berzelius(Annal.deChim. 87— 55) 100 113.6 127.2$
My own, as above 100 113.4 127
* By nitric acid, the result of 3 experiments all agreeing
for the deutoxide ; the protoxide is by calculation and less
certain. He afterwards adopts 13.6 from Berzelius. Journ.
de Phys. Aug. 1814.
f The protoxide from hydrogen by solution; the deut-
oxide by transmitting steam over the metal at a red heat.
t The 2d. by oxydizing the sulphuret of tin by nitric
acid; the 1st. by inference only, one half of the oxygen
of the 2d.
METALLIC OXIDES. 39
13. Oxides of Lead.
There are three oxides of lead now gene-
rally recognized, the yellow, the red, and
the brown, the proportion of oxygen in each
of which has been investigated by several
chemists whose results do not well accord
with each other. I shall treat of them under
the following names, namely the protoxide,
the intermediate oxides, and the deutoxide, for
reasons which will appear,
1. Protoxide. The yellow oxide of lead is
the only one capable of forming salts with
acids. Lavoisier found the oxygen of this
oxide combined with 100 lead to be 4.47 j
Wenzel, 10; Proust, 9; Thomson, 10.5;
Bucholz, 8; Berzelius, 7.7. This last ac-
cords best with my own experience ; but it is
chiefly from the other combinations of lead,
that the weight of its atom as well as that of
the protoxide are determined and confirmed,
as lead forms several very definite compounds
with acids, &c. The quantity of oxygen in
the protoxide may be found by several me-
thods, as under.
1st. By dissolving a given portion of the
oxide in acetic acid, and precipitating the
lead by another metal, as zinc; in this case
40 METALLIC OXIDES.
the oxygen of the lead goes to the zinc which
becomes dissolved, and from the loss of
weight of the zinc and the proportion of
oxygen in zinc oxide being previously known,
and the weight of the precipitated lead being
found, we have data for determining the ox-
ide of lead. I took 200 measures of acetate
of lead solution (1.142), which I knew con-
tained 27 grains of oxide of lead ; this being
diluted with an equal volume of water, the
lead was precipitated by a rod of zinc ; in
6 hours an arbor saturni was formed which
was collected and well dried; it weighed 21 f
grains, and the zinc rod had lost 7 grains :
cafe must be taken in performing this expe-
riment that all the lead be not precipitated,
otherwise the oxide of zinc begins to fall,
and the result is uncertain. In the residuary
liquid I got 4 grains of sulphate of lead by
sulphuric acid. Here then we have the oxy-
gen of 21 1 lead transferred to 7 zinc; but
if 7:21f ::29:90 nearly. Now it is known
that 29 parts of zinc take 7 of oxygen, there-
fore 90 lead take 7 of oxygen, and the atom
of lead=90, and the protoxide 97.
I formerly stated the atom of lead 95.
Vol. 1, page 260.
2. By dissolving 180 grains of lead in ni-
tric acid in a small thin capsule, and heating
METALLIC OXIDES. 41
it till the salt was quite dry, I got 288 grains
of salt, weighed in the capsule; 36 grains
of this salt yielded 24J yellow oxide by a low
red heat=22§ lead. This gives 90 lead to
7 oxygen.
3d. Again, 36 grains of the above salt,
dissolved in water, precipitated by ammonia,
and well washed on a filter, gave 23 4* grains
of oxide separated from the filter, and this
had acquired 1 grain, making 24 + grains of
oxide from the 22 f lead as before ; the resi-
due of liquid gave no signs of lead by hydro-
sulphuret of ammonia. The same quantity
of salt precipitated by an excess of lime wa-
ter gave only 22 grains of oxide ; but hydro-
sulphuret of ammonia precipitated 2 4. grains
of sulphuret of lead from the clear liquid.
II. Intermediate oxide or oxides. Minium
or red lead, &c. Minium is an article of
commerce used as a pigment and for various
other purposes. It is made by exposing the
yellow or protoxide of lead finely pulverized
to a low red heat in a current of air, and con-
stantly stirring the oxide so as to expose fresh
particles to the air. In two days the yellow
oxide is converted into the red. Several au-
thors observe that red lead usually contains
1,2, or more grains per cent, of impurities
insoluble in nitric and acetic acids; the spe-
VOL. II. F
42 METALLIC OXIDES.
cimen I used however was so pure as not to
leave more than 4- of a grain per cent, of
insoluble matter after being heated red and
treated with dilute nitric acid.
Some of the most remarkable properties
of red lead are, 1st. It is never obtained in
combination with any acid; 2d. It yields
oxygen gas when exposed to a bright red heat
or when treated with concentrated sulphuric
acid, and is in both cases reduced to the pro-
toxide; 3d. When treated with dilute nitric
acid it is dissolved in part, but constantly
leaves an insoluble brown residuum, which is
the deutoxide, as will be shewn; the weight
of the deutoxide obtained is by my experi-
ments 20 per cent, and the part in solution is
found to be the protoxide; 4th. When treated
with muriatic acid, muriate of lead is formed
and, oxy muriatic acid given out; 5th. When
treated with dilute acetic acid or cold con-
centrated acetic acid, \ of the oxide is dis-
solved and the remainder is still red, its co-
lour being rather improved; if concentrated
acid be used and boiling heat applied, then
4. of the whole oxide ia dissolved and ~ re-
mains of brown oxide, the same as with ni-
tric acid.
Some of the above facts are new, and
may contribute to elucidate this most curious
METALLIC OXIDES. 43
oxide, which scarcelyhas a parallel. Proust
is the only author I know who has given a
plausible conjecture concerning the peculiar
nature of this oxide. He supposes it a com-
pound of the yellow and brown oxides.
This I believe is the fact ; but it will be found
I apprehend to be a compound of 1. atom of
oxygen with 6 of the yellow oxide, as will
appear from what follows.
Respecting the quantity of oxygen in the
red oxide, Lavoisier finds 9 oxygen to 100
lead, Thomson 13.6, and Berzelius 11.55.
This last is partly from experience and partly
from a supposed analogy, that the successive
oxides of the same metal contain oxygen as
1, If and 2 respectively ; and having found
(I believe) correctly, that the brown oxide
contains just twice as much oxygen as the
yellow, this ingenious and generally accurate
author adopts the theoretic inference in this in-
stance at least prematurely, and concludes
the red oxide is the mean between the yellow
and the brown. But we must appeal to ex-
perience.
It has already been stated that when red
lead is exposed to heat, oxygen gas is given
out, and it may be added, a small trace of
water; and yellow oxide remains.
44 METALLIC OXIDES.
This experiment requires considerable
skill. If too great a heat is used, a part of
the lead is reduced or revived as it is termed;
if too little heat, then a part of the red lead
remains unaltered. In performing this expe-
riment I use a small clean iron spoon to hold
the red lead, and cover it by another iron
spoon ; the whole is then held by a pair of
tongs in a red fire till the spoon exhibits a
uniform moderate red, and some time after.
It is then withdrawn and cooled, and the
oxide weighed. The average loss of weight
is nearly 2 grains per cent. If only 1 grain
or less, a considerable portion of red oxide
remains mixed with the yellow; if 3 or more
grains, then the margin of the oxide exhi-
bits particles of lead amounting to TV> less
or more, of the original weight; this can be
easily separated from the oxide if necessary,
but it is apt to adhere to the iron ; when red
oxide remains, it is so mixed with the yellow
as not easily to be separated, but its quantity
may be determined by nitric acid, which dis-
solves the yellow, and £ of the red, leaving
a residuum of brown oxide, from which the
quantity of red is inferred. Now if the loss
of weight of 100 red oxide be only 2 grains,
and a part of that be water, it is impossible
METALLIC OXIDES. 45
that 115.55 should lose 3.85 grains of oxygen,
according to Berzelius. Another experiment,
equally decisive of the question, is to deter-
mine the quantity of oxygenous gas to be ob-
tained by heat or acids from a given weight
of red lead. In one experiment made with
great care, 500 grains of red oxide gave 6
grains of oxygenous gas by sulphuric acid;
in another, 200 yielded 2 J grains. In order
to vary the mode of determining the quantity
of oxygen, into 210 measures of test green
sulphate of iron solution, (1 .156) = 16.8 green
oxide, put 160 grains of minium; to this
was added dilute muriatic acid more than
sufficient for the minium : The oxymuriatic
acid from the oxygen of the minium was in-
stantly seized by the oxide of the iron, the
whole of which was found by precipitation
to be changed from green to red and an ex-
cess of oxymuriatic acid appeared. Now
16.8 oxide would require 1.86 oxygen to be-
come red, which it must have acquired from
160 of red lead; or 100 red lead yielded 1.2
oxygen, the same proportion as by sulphuric
acid. These experiments point out 1.2 oxy-
gen in 100 red lead as the excess which con-
verts the yellow to the red oxide. Were
any doubt to remain on the subject, the ex-
periment with nitric acid and red oxide will
46 METALLIC OXIDES.
remove it. If the red oxide contained a mean
of oxygen between the yellow and the brown,
when it is treated with nitric acid more than
50 per cent, of brown oxide would be ob-
tained instead' of 20, which is contrary to
all experience. It must be observed that
Berzelius informs us he extracted the yellow
oxide, mechanically mixed (as he conceives)
with the red oxide, by digestion with dilute
acetic acid; but he does not inform us how
much per cent, his minium was reduced by
this operation. From what is stated above,
it appears that about J- of the whole is thus
dissolved. The remaining half would then
contain double the quantity of oxygen and
brown oxide per cent, that the original did.
Still these quantities are inadequate to explain
the phenomena. Besides it cannot be admitted
that a red and a yellow powder can be inti-
mately mixed in equal quantities and the
mixture not be distinguishable without diffi-
culty from the red one, and be altogether dif-
ferent from the yellow. We must then con-
clude that the minium of commerce (such as
I have used) is a true chemical compound.
Grounding our reasonings upon the preced-
ing facts, there are but two suppositions that
can be considered as plausible, respecting the
constitution of the red oxide. It may be 1
METALLIC OXIDES. 47
atom of oxygen and 5 of yellow oxide, or I
atom of oxygen and 6 of yellow oxide. The
former would give 1.4 per cent, extra oxygen
in 100 red oxide, and 21 brown oxide; the
latter would give 1.2 per cent, extra oxygen
and 18 brown oxide. I adopt the latter sup-
position ; because it agrees with experiment
in regard to oxygen, and gives the brown ox-
ide a little lower than experiment, as may be
expected on two accounts; first, the residue
of brown oxide contains the insoluble dross of
the red oxide (which was very small however,
as stated above) ; and, second, unless a con-
siderable excess of nitric acid be used, or long
digestion, a small portion of the red oxide es-
capes decomposition. Another and still more
important consideration, as to the question
whether 5 or 6 atoms, is the equal division of
the red oxide by the operation of cold acetic
acid; it reduces the 1 oxygen and 6 yellow
oxide to 1 and 3 atoms; whereas if we adopt
the other, we must conclude it reduces the 1
and 5 to 1 and 2|, a position that cannot well
be reconciled to the atomic theory.
According to this conclusion then the red
oxide of lead or minium of commerce is con-
stituted of 1 atom of oxygen holding 6 atoms
of yellow oxide together; or it is composed
of 100 lead and 9.07 oxygen. When it is
48 METALLIC OXIDES.
digested in cold acetic acid the residuum con-
stitutes another oxide consisting of 1 atom of
oxygen and 3 of yellow oxide, or 100 lead
and 10.4 oxygen, possessing the same colour
as the former, but distinguishable by its not
being acted on by cold acetic acid, and by its
containing twice as much brown oxide and
extra oxygen as minium. No doubt the other
intermediate oxides of 1 to 4 and 1 to 5 exist,
and are all alike red; but have not perhaps
any remarkable distinctions besides their
containing different proportions of oxygen
and brown oxide. Whether an oxide consist-
ing of 1 oxygen and 2 yellow oxide exists, I
have not discovered; but that 1 oxygen and
1 yellow oxide are found united, appears
below.
III. Deutoxide. This is the flea-brown ox-
ide mentioned above. It may also be obtained
by treating solutions of salts containing the
yellow oxide by oxymuriate of lime, in
which case the oxide is precipitated, leaving
the acid in the liquor, a proof that it is inso-
luble in acids. Its more remarkable proper-
ties are : 1st. like the red oxide, when heated
to a low red, or treated with sulphuric acid,
it yields oxygenous gas, and more copiously;
it is thus reduced to the yellow oxide: 2d.
with muriatic acid it yields oxymuriatic acid
METALLIC OXIDES. 49
in great plenty and muriate of lead : 3d. it
detonates when rubbed with sulphur in a
mortar.
The quantity of oxygen in the brown ox-
ide is stated by Thomson at 25 oxygen to 100
lead, by Berzelius at 15.6 to 100. This last
is very nearly right by my experience, and
being just double of the oxygen in the prot-
oxide, it warrants us in denominating it the
deutoxide. Berzelius finds 100 of the brown
oxide lose 6.5 by a red heat so as to reduce it
to the yellow; Dr. Thomson finds the loss 9
grains. This difference is easily accounted
for; it loses, I find, from 7 to 10 grains per
cent, according to the previous degree of
dryness ; when exposed to a moist atmosphere
it attracts humidity; when dried in a tempe-
rature of 200° and exposed to red heat imme-
diately after, it does not lose more than 6.5 or
7 per cent. This is corroborated too by the
oxygen expelled by sulphuric acid. From
100 grains of brown oxide and sulphuric acid
in a gas bottle, I obtained by the heat of a
lamp 8.3 oz. of oxygenous gas = 5.3 grains;
about 120 grains of grey sulphate of lead
were left in the bottle. The oxygen is rather
less than was expected; but it must be re-
membered that 100 grains of brown oxide,
obtained in the ordinary Way, have the inso-
YOL. II. O
50 METALLIC OXIDES.
luble dross of 500 red oxide in them, which
must have some influence in diminishing the
production of oxygen.
Though the above might be deemed suffici-
ent to demonstrate the proportion of oxygen
in the brown oxide, I was desirous to corro-
borate the results by oxy muriate of lime.
I found repeatedly that 100 grain measures of
acetate of lead (1.142) = 13.8 yellow oxide,
required 400 measures of oxy muriate of
lime=l oxygen, to precipitate the whole of
the oxide in a brown state. Now if 13.8 : 1 ::
97:7. Again, into 240 measures of test
green sulphate of iron (1.156) = 19 oxide,
were put 40 grains of brown oxide of lead,
together with a sufficient quantity of muria-
tic acid to saturate the lead, and discharge
the oxygen; after due agitation sulphate of
lead was precipitated, and the whole of the
oxide of iron was found, when precipitated, to
be yellow. But 19 grains oxide of iron re-
quired + of oxygen to become yellow; hence
the 40 grains brown oxide of lead must have
furnished 2 + grains of oxygen to form oxy-
muriatic acid, which transferred it to the oxide
of iron. If 40:2+ :: 100 i5+ oxygen, for the
excess or secoridtioseof oxygen in 100 brown
oxide, such as is obtained/by nitric acid along
" tlniii '■ ; ]r
METALLIC OXIDES. 5}
with its impurities; which agrees with the
results obtained by the other methods.
14. Oxide of zinc.
When zinc is exposed to a strong heat it
burns with a brilliant white flame, and
a white powder sublimes, which is the oxide
of the metal. When dilute sulphuric acid is
poured on granulated zinc, hydrogen gas is
produced in great abundance and purity; the
metal is oxidized at the expence of the water
and dissolved in the acid, the oxide may be
precipitated by an alkali; it is white both
when precipitated and dried, and when heated
does not differ from that obtained by combus-
tion. By a violent heat it runs into glass.
The quantity of oxygen in zinc oxide is, I
think, best estimated by the hydrogen gas
produced during the solution ; it may also be
obtained by direct combustion, or by solution
in nitric acid and calcination. Dr. Thomson
determines the oxygen by comparison of the
weights of real sulphuric acid and metallic
zinc in a solution of sulphate of zinc, along
with the consideration that the proportion of
sulphuric acid and oxygen in the metallic
sulphates is known ; Mr. Cavendish obtained
356 oz. measures of hydrogen from 1 oz. of
52 METALLIC OXIDES.
zinc by solution. I dissolved 49 grains of
zinc in dilute sulphuric acid and obtained hy-
drogen, after the rate of 363 grain measures
for 1 grain of zinc = 182 measures of oxygen
= .24 grain of oxygen.
The following are the principal authorities
for the quantity of oxygen in zinc oxide, in
the order of lime.
Zinc. Oxygen.
1766. . Cavendish 100 + 23.3
1785. Lavoisier -J- 19.6
1790—1800. Wenzel and Proust ... f- 25
1801. Desorme and Clement 1- 21.7
Davy .„. J- 21.95
Berzelius -f- 24.4
Gay Lnssac — — -j- 24.4
Thomson \- 24.42
My own — — -|- 24
Now if 24oxy. :100 zinc::7 oxy.:29zinc,
nearly, which is therefore the weight of an
atom of this metal, on the supposition that
the oxide is 1 oxygen and 1 metal; and the
atom of oxide = 36.
I formerly estimated the atom of zinc at
56 (Vol. 1, page 260). This was occasioned
by taking the above as the deutoxide instead
of the protoxide. By violently heating the
oxide of zinc in a close vessel, Desorme and
Clement reduced the oxygen nearly one half,
so as to afford a presumption that an oxide
METALLIC OXIDES. 53
with half the oxygen of the common one sub-
sisted. Since that time some observations of
Berzelius seem to shew that a sub-oxide of
zinc exists. It does not appear however, that
such oxide is ever found in combination with
acids; and, granting the accuracy of the ob-
servations, it is rather to be presumed to be
the semi-oxide, or 1 atom of oxygen and 2 of
metal, than the protoxide. No higher oxi-
dation of zinc than the above has yet been
obtained, and probably does not exist.
15. Oxides of potassium.
Since writing' the articles "potassium and
Sodium/' in the former volume, a very impor-
tant essay relating chiefly to these subjects has
been written by Gay Lussac and Thenard (a
copy of which they were so good as to send
me), entitled " Recherches Physico-chimi-
ques, &c." in 2 Vol. — Many of the most in-
teresting experiments of Davy have been re-
peated on a larger scale, and a great number
of original ones added; these ingenious au-
thors endeavour to sum up the evidences for
and against the two hypotheses concerning
potassium and sodium, namely, as to their be-
ing metals or hydrurets, and upon the whole
incline to the former, allowing however, that
54 METALLIC OXIDES.
the facts afford great plausibility to both.
One thing they seem to have discovered and
established, that the new bodies or metals ad-
mit of various degrees of oxidation, and of
course these products have a claim to be classed
amongst oxides in general though the nature
of their bases may still be an object of
dispute.
They find three oxides of potassium ; the
lowest degree is obtained by exposing potas-
sium to atmospheric air in a small bottle, with
a common cork; a gradual oxidation takes
place; a blueish grey brittle product is ob-
tained; there does not appear however, to be
any proper limit to this oxidation besides that
which they admit as characterizing the second
degree or potash, which degree of oxidation
may always be immediately obtained by plac-
ing potassium in contact with water. This I
think should be called the protoxide and con-
sidered as 1 atom of potassium, and 1 of
oxygen ; before this point it is potassium and
pot-ash mixed or perhaps combined.
Besides these there is another obtained by
burning potassium in oxygen gas at an eleva-
ted temperature; this oxide is yellow* fusible
byjheat, and crystallizes in lamina on coolings
it contains three times as much oxygen as pot-
ash ; put into water it is suddenly decomposed*
METALLIC OXIDES. 55
giving out 4. of the oxygen in gas and becom-
ing potash. Very probably an oxide contain-
ing twice as much oxygen as potash might be
formed with some mark of discrimination,
by uniting 18 parts potassium with 56 of yel-
low oxide, but this has not vet been done.
According to these conclusions the weights
of the oxides of potassium may be stated as
under.-— Potassium 35, protoxide or potash
42, deutoxide (supposed to exist) 49, and
the yellow or tritoxide 56. Hence we have
Potassium. Oxygen.
Protoxide (potash) 100 -f- 20 7 Gay Lussac & Thenard
19 j Davy
Deutoxide 100 + 40 (unknown)
Tritoxide 100 + 60 Gay Lussac & Thenard
One feels unwilling to admit of a tritoxide,
(and that perhaps the only one existing,)
when the deutoxide is unknown, were it not
upon good authority. The obscurity on this
subject may be removed by future expe-
riments.
It may be proper to add that Gay Lussac
and Thenard concur with Davy in assigning
a much greater saturating power to potassium
and sodium than to the fused hydrates of pot-
ash and soda of equal weights. From the ta-
ble, Recherches, Tom. 2, p. 214, it may be
deduced that 35 potassium require as much
56 METALLIC OXIDES.
sulphuric acid to saturate them as 50 or more
of the hydrate of potash; and that 21 sodium
are equivalent to 36 or 37 hydrate of sodium.
If these results are accurate, the weights of
potassium and sodium, considered as hydru-
rets, cannot be as we have deduced them at
pages 486 and 503, Vol. 1, namely, 43
and 29 respectively, but 35 and 21, as at
page 262.
16. Oxides of sodium.
Gay Lussac and Thenard find a suboxide
of sodium in the same way as that of potas-
sium, and it is probably a compound of soda
and sodium : the remarkable oxidation which
produces soda is, I should imagine, the prot-
oxide or one atom to one, as obtained by
placing sodium in contact with water. A
higher oxide is obtained as with potassium,
by burning sodium in oxygen gas with a vi-
vid heat. It resembles the yellow oxide of
potassium in its appearance and properties.
The degree of oxidation varies in the differ-
ent experiments from 1^ to l.-|- times the
oxygen of soda. It is probably a combina-
tion of the protoxide and deutoxide. Hence
the oxides of sodium may be as under; reck-
oning the atom of sodium 21, and soda 28.
METALLIC OXIDES. 57
Sodium. Oxygea.
Protoxide (Soda) 100 + 33*
Intermediate oxide 100 -j- ^0
17. Oxide of bismuth.
Only one oxide of bismuth is known, and
the proportion of its parts has been gradu-
ally approximated by Bergman, Lavoisier,
Klaproth, Proust, and others. Berzelius
mentions a purple oxide obtained by exposing
bismuth to the action of the atmosphere;
but as no experiments have been made upon
it, we cannot adopt it at present. According
to Klaproth and Proust, 100 bismuth unite
with 12 oxygen; but by the more recent ex-
periments of Mr. J. Davy and Lagerhjelm
100 bismuth take 11.1 or 11.3 oxygen. If
we adopt this last, which is doubtless near
the truth; we shall have 11.3: 100:: 7:62 for
the weight of the atom of bismuth, on the
supposition that the compound is the protox-
ide or 1 atom of metal to 1 of oxygen. My
former weight of bismuth was 68 (page 263),
which is clearly too high.
Bismuth is best oxidized by nitric acid.
Part of the oxide combines with the acid and
part precipitates in the state of a white pow-
der; if the whole be gradually heated, the acid
VOL. n. H
58 METALLIC OXIDES.
is driven off, and at a low red the oxide re-
mains pure; it is fused into glass and of a red
or yellow colour, according to the heat em-
ployed. Bismuth may also be oxidized by
heat in open vessels ; yellow fumes arise which
may be condensed and are found to be the
oxide.
18. Oxides of antimony.
Considerable difference of opinions exists
with regard to the oxides of antimony.
Proust finds two oxides which he determines
to consist, the first, of 100 metal + 22 or
23 oxygen ; the second of 100 metal + 30
oxygen. Thenard finds 6 oxides: J.Davy
two oxides, namely, 100 metal + 17.7 oxy-
gen, and 100 4- 30 oxygen. Berzelius infers
from his experiments that there are 4 oxides
of antimony, the first containing 4.65 oxy-
gen, the second 18.6, the third 27.9, and the
fourth 37.2 of oxygen on 100 metal. He ad-
mits however that the oxide obtained by boil-
ing nitric acid on antimony and expelling the
superfluous acid by a low red heat, consists of
100 metal -I- 29 to 31 oxygen, as determined
by Proust and others. This is certainly the
most definite of the oxides, next to that which
is obtained from the solution of antimony in
METALLIC OXIDES. 59
muriatic acid. This last may be had by
pouring water into a solution of muriate of
antimony ; a white powder precipitates, which
is the oxide with a little muriatic acid ; the
acid may be abstracted by boiling the preci-
pitate in a solution of carbonate of potash.
This oxide is a grey powder, and fusible at
a low red heat. It enters exclusively into va-
rious well known compounds, as the golden
sulphur of antimony, antimoniated tartrate of
potash, &c. Its constitution, according to
Proust, is 100 metal + 23 oxygen ; but J. Da-
vy finds only 17.7 oxygen, andBerzeliiis 18.6.
As this oxide possesses the most distinct fea-
tures, and besides is the most important; it is
desirable its constitution should be ascertained
without doubt. From several experiments I
made on the precipitation of antimony by
zinc, I conclude the oxide contains about 18
oxygen on 100 metal. I took the common
muriate of antimony with excess of acid, and
immersed a rod of zinc into it, covering the
whole with a graduated bell glass. Hydrogen
gas was produced by the excess of acid, and
its quantity was ascertained; the antimony
was in due time precipitated, and when the
operation ceased, the loss of zinc and the
weight of antimony were found. For in-
stance, to 50 measures of 1.69 mur. ant. 60
60 METALLIC OXIDES.
water were added, no precipitation was ob-
served; a zinc rod was put in and the whole
covered by a bell glass, over water; in a
few hours the operation had ceased, and there
appeared 3480 grain measures of hydrogen
gas generated ; the dried antimony weighed
25f grains, and the zinc had lost 29 grains.
Now 3480 hydrogen require 1740 of oxygen
= 2.3 grains in weight. But 29 zinc require
7 oxygen; therefore the zinc must have got
4.7 oxygen from the antimony; that is, 25.5
antimony; were found united to 4.7 oxygen;
this gives 100 antimony +18*4 oxygen. I
conclude then that the error is with Proust;
and this appears to be confirmed by the con-
sideration that Proust himself obtains only 86
oxide of antimony from 100 sulphuret, which
he allows to contain 74 antimony; now if 74:
12 :: 100: 17 nearly. I am therefore inclined
tp adopt 18 for the oxygen which combines
with 100 antimony to form the grey oxide.
Whether this is the protoxide or deutoxide
may be disputed; and the facts known con-
cerning the other oxide or oxides will scarcely
determine the case : but the : proportions of
the muriate and sulphuret of antimony accord
imjch better with the former supposition.
Now if; 18:100 ;7: 39, for the weight of the
atom; of antimony ; I prefer the weight 40,
METALLIC OXIDES. 61
deduced from the sulphuret, as announced in
Vol. 1, page 264.
The oxide which contains 30 on 100 must
be 2 atoms of the deutoxide and 1 of the
protoxide united. What Berzelius calls the
white oxide or antimonious acid, may be 1
atom of each oxide united, containing 27
oxygen on the 100. The oxide supposed to
contain 36 or 37 oxygen on 100, and which
must be considered as the deutoxide, has not
been proved to exist separately. My efforts to
procure it have failed as well as those before
mine : by treating muriate of antimony with
oxymuriate of lime I have obtained oxides
of 30 on the 100, but never much higher.
Whenever a greater proportion of oxymuri-
ate of lime is added, the smell of the gas be-
comes permanent.
Antimony exposed to a red beat in a current
of common air or oxygenous gas takes fire,
and white fumes arise formerly called flowers
of antimony \ this oxide contains 27. or 30
oxygen on 100 metal.
Antimony thrown into red hot nitre is oxi-
dized rapidly ; the remaining powder, washed
in water, is found to be a compound of oxide
of antimony and potash. Berzelius calls the
oxide the antimonic acid, and the salt the
antimoniate of potash. It consists, according
62 METALLIC OXIDES.
to his experience, of 100 acid and 26.5 pot-
ash. A similar salt formed between the anjti-
monious acid and potash is constituted of 100
acid and 30.5 potash.
19. Oxide of tellurium.
We are chiefly indebted to Berzelius for
the proportions in which tellurium combines.
He finds 100 tellurium unite to 24.8 oxygen.
Also that 201.5 tellurate of lead gave 157
sulphate of lead. This last contains 116 ox-
ide of lead, which must therefore have com-
bined with 85.5 of the oxide of tellurium.
Hence 97 oxide of lead would combine with
71.5 oxide of tellurium = 57§ tellurium +14
oxygen. Whether this oxide of tellurium is
the protoxide or deutoxide, is somewhat un-
certain. The atom of tellurium will weigh
57 1 in the latter case, but only 28 or 29 in the
former. The analogy of the oxide to acids
favours the notion of a deutoxide; but the
facility with which the tellurium is volatilized
by hydrogen is in favour of the lighter atom.
The oxide is a white powder; it is produced
by dissolving the metal in nitro-muriatic acid
and precipitating by an alkali.
METALLIC OXIDES. 63
20. Oxides of arsenic.
There are two distinct combinations of ar-
senic and oxygen; the one has been long*
known as an article of commerce under the
name of arsenic. It is a white, brittle, glassy
substance, obtained during the extraction of
certain metals from their ores. Its specific
gravity is about 3.7. According to Klaproth
boiling water dissolves from 7 to 8 per cent,
of the oxide of arsenic; but on cooling it
retains only about 3 per cent.; and this I find
is gradually deposited on the sides of the ves-
sel till it is reduced to 2 per cent, or less in
cold weather, and by some months standing.
Water of 60° degrees or under dissolves no
more than J per cent, of the oxide. At the
temperature of about 400° the oxide sublimes*
This oxide combines with the alkalies, earths,
and metallic oxides somewhat as the acids do,
but does not neutralize them, and in other
respects it is destitute of acid properties; as
for instance, it does not affect the colour tests.
It is extremely poisonous.
The other oxide is obtained by treating
either the white oxide or pure metallic arsenic
with nitric acid and heat. One hundred
grains of white oxide require two or three
times their weight of nitric acid, of 1.3, to
64 METALLIC OXIDES.
oxidize them. The new oxide is produced
in a liquid form ; from which the excess of
nitric acid may be driven by a low red heat,
and the oxide is obtained pure in the form of
a white opake glass, which soon becomes li-
quid by attracting moisture from the atmo-
sphere. This oxide, discovered by Scheele,
has all the properties of acids in general, aud
is therefore denominated arsenic acid. When
just fluid by attracting moisture it has the
sp. gravity 1.65 nearly. It is represented as
equally poisonous with the white oxide.
The proportions of the elements in these
two oxides have been investigated with con-
siderable success. Proust finds the white
oxide constituted of 100 metal and 33 or 34
oxygen, and the second of 100 metal with
53 or 54 oxygen: with these results those of
Rose and Bucholz nearly agree. Thenard
finds 100 +34.6 for the white oxide, and 100
+ 56.25 for the acid: and Thomson 100+52.4
for the acid. Eerzelius however, infers from
his recent experiments that the oxide consists
of 100 metal +43.6 oxygen, and the acid of
100+71.3; these last results I have little
doubt are incorrect from my own experience.
It appears that when arsenic is oxidized by
nitric acid, 100 parts yield from 152 to 156
of acid, dried in a low red heat. The differ-
METALLIC OXIDES. 65
ences may in part be owing to the metal being
partly oxidized at the commencement of the
operation. On this account I should suppose
55 or 56 to be the proper quantity of oxygen
united to 100 metal to form the acid. Proust
and Thenard both found that 100 white oxide,
when converted into acid by nitric acid¥ gave
115 or 116. I have found the same., ) Now
if 116: 100:: 156: 134 ; hence the white ox-
ide of arsenic must contain 100 metal to 34
oxygen, if the data be correct; or the metal
and oxygen are as 3 to 1 nearly. It is highly
improbable that any inferior oxide subsists,
as no traces of such have been found, if we
disallow a conjecture of Berzelius on the
subject. The white oxide of arsenic must
then be considered as the protoxide, and the
atom of arsenic must weigh 21 nearly, and
that of the protoxide 28.
It i$ plain the other is not the deutox-
ide, as it does not contain twice the, oxygen
of the protoxide; but as the proportion of
oxygen in it is to that of the protoxide, as
5:3, it may be a compound of 2 atoms of
deutoxide, and 1 of protoxide; that is, it
may be the superarseniate of arsenic, if we
consider the deutoxide as the acid, and the
protoxide as the base. According to this
view, the compound oxide, or arsenic acid of
VOL. II. I
66 METALLIC OXIDES.
Scheele, is constituted of two atoms of the
d^utoxide, weighing 70, and 1 atom of the
protoxide weighing 28, together making 98,
for;the weight of an atom of arsenic acid, =6$
arsenic + 35 oxygen : and 100 arsenic take
55.5 oxygen to form the acid, agreeably to
the above recited experiments. Singular as
this conclusion may appear, the tr nth of it
is put %&yoftd dotibt^ I think, by the follow-
ing experiments.
I have repeatedly found that 28 parts of
white ox itle in solution are sufficient to throw
down-84 parts of lime, from lime-water, so
as to produce' 52; parts of arsenite of lihle,
and leaVd'the^te^ free from both elements.
1Fft& cotoftritts the riotiou of the atom of prot-
oxide w^igh^ s
bt(M to 24pairts of lime dissolved -in > water
we put 98 parts of dry arsenic acid, 'the com-
pound < remains in soldtion, and is perfectly
neutral to the colour test^ but so that the addi-
tion of !&( Ismail quantity of either ingredient
disturbs the -neutrality.' If to this solution 24
parts Of lime dissolved in water be added,
the compound remains a limpid solutiou; f but
is very< limy to the test. If to this we putin
like- manner^ 24 parts more of lime, the
whole compound is throwu down, and yields;,
wh^n dried, 170 parts bfarseniate of lime,
METALLIC OXIDES. 67
the liquid being now free from both ele-
ments. Here we see first, two atoms of
the deutoxide, neutralized by two atoms of
base, namely, 1 of arsenic oxide, and 1 of
lime; but (second), when one atom more of
lime is added, an union of 2 deutoxide, and
3 of base is effected, which of course is an
alkaline salt; when (third) more of limeis add-
ed, the 2 deutoxide and the 1 protoxide each
attach 1 of lime, and form a still more alka-
line salt, which being- insoluble, is wholly
thrown down, most probably in a compound
state of 98 parts arsenic acid, combined with
72 parts lime.
In like manner, I find that 42 parts of pot-
ash, 28 of soda, and 12 of ammonia, seve-
rally neutralize 98 parts of arsenic acid.
1st. 24 lime -f- 32.7 arsenic acid c== insoluble arseuiate
2d. : — — -j- 49 — = soluble arseniate
3d. -f- 98 — — = neutral arseniate
It is a remarkable fact, that when neutral
arseniate of potash and nitrate of lead are
mixed together to mutual saturation, the pre-
cipitate is found to consist chiefly of arsenic
acid and oxide of lead, in proportion of 1
of acid to two of oxide, (that is, 98:194,
or 100 : 198) ; which does not differ much from
the determination of Berzelius.
68 METALLIC OXIDES.
I find however, only one fourth of the
nitric acid in the residuary liquid in a free
state; which leads me to suspect that the pre-
cipitate is a compound of subnitrate and ar-
seniate of lead, in which the arsenic acid
and lead are in due proportion, or 98 acid,
to 97 oxide. This consideration may be
properly resumed hereafter.
Hence we conclude, the atom of arsenic
weighs 21 (and not 42, as at page 264,
Vol. 1), that of the protoxide or common
white arsenic, 28; and that of arsenic acid
= 98, being a compound of 2 atoms of deut-
oxide, and 1 of protoxide. Or,
100 Arsenic -f 33.3 oxygen = 133.3 protoxide
• + 55.5 = 155.5 arsenic acid
21. Oxides of cobalt.
There are at least two oxides of cobalt,
the one blue, the other black. Authors differ
as to the proportions of the elements. Proust
states the blue oxide to consist of 100 metal,
and 19 or 20 oxygeij, and the black of 25 or
26 oxygen. Klaproth finds in the blue, 100
metal and 18 oxygen. But Rolhoff accord-
ing; to Berzelius, finds 100 metal and 27.3
oxygen in the blue oxide, and 40.9 in the
black. I have taken some pains to invests
METALLIC OXIDES. 69
2fate these oxides, and have been able to sa-
tisfy myself in a good degree, respecting
their constitution. The blue or protoxide
consists of 100 metal and 19 oxygen, and
the black oxide of 100 metal, and 25 or 26,
very nearly as Proust determined.
Protoxide. By repeated trials 1 have found,
that if 37 parts of metallic cobalt be treated
with the due quantity of nitro-muriatic acid,
and a heat of 150% a rapid solution takes
place, and a disengagement of pure nitrous
gas; this being carefully collected, it will be
found to weigh 8 grains, and of course corres-
ponds to 7 grains of oxygen; hence 37 co-
balt, unite to 7 oxygen, to form 44 of the
blue oxide; and as this is the only oxide that
combines with acids, it must be considered
as the most simple or protoxide, being 1 atom
of metal (37), and 1 of oxygen (7). The
estimation of the atom of cobalt at 50 or 60,
(page 265), must therefore be corrected.
Compound oxides. When the blue oxide of
cobalt is precipitated from, a solution, by an
alkali or lime water, and oxymuriate of lime
is gradually dropped in, the precipitate chan-
ges colour rapidly; it passes from blue to
green and olive, thence to a dark bottle green,
and finally becomes black; oxygen gas is
given out copiously when an excess of oxy-
70 METALLIC OXIDES.
muriate of lime is used. I find the addi-
tional oxygen requisite to convert the blue
to the black oxide is what Proust states it,
namely, -f of that necessary to form the blue;
hence it must be considered as a compound of
1 atom of oxygen and 3 of the protoxide.
Probably the other coloured oxides are 1 to
4, 1 to 5, &c* The protoxide is blue when
precipitated, but it is supposed to contain
water, or to be a hydrate ; as it is dark grey
when heated. The blue oxide in: a short
time after precipitation being still under wa-
ter, changes to a yellowish or dead-leaf co-
lour; which also appears to be a hydrate qf
the protoxide, as it .dissolves in acids without
giving out /gas, and yields the blue oxide by
an alkali* According to Proust, this hydrate
contains £0 or 2 1 per cent, water. If we sup-
pose the blue to be 1 atom oxide, and 1 wa-
ter, the yellow hydrate may be 1 water and 2
of the proto-hydrate ; or 88 oxide, and 24
water, which will be nearly 21 per cent,
water.
The black oxide gives out oxygen gas by
<i red heat, and is reduced to the grey oxide :
it forms oxymuriatic acid, with muriatic acid,
and the protoxide remains in solution.
(See Tassaert.— An. de Chimie28; The-
nard, 42; and Proust, 60.)
METALLIC OXIDES. 71
22* Oxides of manganese*
One of the oxides of manganese being a
natural production, and sometimes of great
purity, and the metal not being obtainable
without skill and labour, it may be most con*
venient to adopt the inverse method in our in-
vestigations; that is, to trace out the atom of
metal from its oxides.
Native oxides of manganese. Of late, I have
met with excellent specimens of this oxide;
they are in masses of a greyi crystalline ap-
pearance, sp. gr. 4, easily pulverizable into a
greasy, shining, dark grey powder. They
are nearly pure oxide; but the niore common
sort is blacker, and contains less or more
of siliceous earth. Some specimens are very
harsh, require an iron mortar to pulverise
i • K >rrif fff» • feu
them, and contain 50 or upwards per cent, of
siliceous earth. Of the common sort when
pulverized, the black inclining to blue, is ge-
nerally preferable to the black inclining to
brown. I have not observed any earthy car-
bonates mixed with ihe oxide of manga-
nese. Amongst various specimens I obtained
the following analyses.
72 METALLIC OXIDES.
Oxide. sand and in*
« soluble matter.
1. Grey, crystallized oxide 100 — -
2* Pulverized black oxide, from 7 ftft 9n
a bleacher, reputed good j
3. Another specimen, in the lump 77 23
4. A light brown oxide 47 53
5. A sparry oxide, abounding with? g7 .„
flint ) black brown when pulverized )
Some of the chemical characters of the
native oxide of manganese are, its giving
oxygen gas by a red heat, its insolubility in
nitric and sulphuric acids, and its solubility
in muriatic acid, but with the accompanying
circumstance pf disengaging oxymuriaiic
acid.
All these facts shew that it is of the higher
order of oxides, or analogous to the brown
and red oxides of lead.— The muriatic acid
solution abovementioned, contains an oxide
of an inferior degree, which is soluble in all
acids, and which is the only oxide of manga-
nese that appears to be soluble in acids. If
this be considered, (as it may with the great-
est probability), the protoxide, then it will
appear from what follows, that the common
native manganese is the deutoxide, and that
there is an intermediate one, which contains
a mean quantity of oxygen.
METALLIC OXIDES. 73
Protoxide. This may be obtained in solu-
tion with muriatic acid as above, from the
native oxide. Or the black oxide may be
mixed with sulphuric acid into a paste, and
heated in an iron spoon to redness; the mass
being lixiviated, a solution of the protoxide
in sulphuric acid is obtained, generally with
a slight excess of the acid; in this process
heat and the presence of sulphuric acid, ex-
pels the redundant oxygen of the black oxide,
and reduce it to the protoxide, which hence
becomes soluble. If in either of these solu-
tions any oxide of iron be present, whether
from the manganese, or acquired during the
manipulation, it is easily discovered, and se-
parated, as I have frequently found. Into
any solution containing a mixture of the ox-
ides of manganese, the green oxide of iron,
and the red oxide of iron, let lime water be
gradually poured ; the red oxide of iron will
be first precipitated, next; the green oxide,
and lastly the oxide of manganese, which
may hence be separated from each other.
Iron may also be discovered and separated by
carbonate of potash, which must be dropped
into the solution as long as any coloured pre-
cipitate appears; as soon as it has subsided,
the snow-white carbonate of manganese suc-
ceeds. This white carbonate may be very
VOL. II. K
74 METALLIC OXIDES.
conveniently used for obtaining solutions of
pure manganese in any of the acids.
When a solution of pure manganese is
treated With lime water, or ammonia, a light
buff oxide, not much differing in appearance
from the yellow oxide of iron, is obtained.
This oxide is soluble in all acids, when re-
cently precipitated; but, such is its avidity
for oxygen, with moderate agitation of the
liquid it acquires oxygen and becomes brown,
when it ceases to be totally soluble; if dried
in the air quickly, it becomes brown and ob-
tains considerable oxygen. The buff oxide
recently precipitated, is probably a hydrate;
for, when the white carbonate of manganese
is heated gradually to red, the water and the
acid are both expelled, and a, grey powder
Remains; this is quite black on the surface of
the mass, if exposed to the air during the
process. Probably this grey powder is the
ptire protoxide ; it is soluble in acids, except
the black powder at the surface ; perhaps
but for the oxygen of the air, the protoxide
would be nearly white.
From its combinations with sulphuric and
carbonic acids, I find the weight of an atom
of the protoxide to be 32, or the same as that
of iron. Dr. John, a German chemist, who
seems to have investigated these salts with
. ■
METALLIC OXIDES. 75
more attention than any other person, has de-
duced nearly the same results. (Annals of
Philos. 2—172). He finds 33^- sulphuric acid
4*31 oxide, and 34.2 carbonic acid +55.8
oxide; that is, when reduced to compare with
my results, 34 sulphuric acid + 31.3 oxide,
and 19.4 carbonic acid + 32 oxide. This near
agreement may be considered as a confirma-
tion of the accuracy of both. Dr. John finds,
as I have done, three distinct oxides of man-
ganese, the greyish green, the brown, and
the black. The first of these is the only one
that combines with acids ; but we differ mate-
rially as to the quantity of oxygen in each.
He found manganese decompose water at the
ordinary temperature ; by oxidizing the me-
tal this way, 100 metal acquired 15 oxygen
to constitute the protoxide; according to this,
28 metal + 4 oxygen would make 32 prot-
oxide; but this conclusion would be so con-
trary to all analogy, that it cannot be admit-
ted as satisfactory. The probability is, that
the manganese must have contained a little
oxygen at the commencement of the experi-
ment. The general analogy of manganese
to iron, lead, &c. requires that 32 protoxide
should contain 7 oxygen. If this be allowed,
we have the atom of manganese = 25, and
not 40, (as at page 266, Vol. I), the same as
76 METALLIC OXIDES.
that of iron : and this conclusion is corrobo-
rated by what follows.
2. Intermediate or olive brown oxide. This
may be formed by combining oxygen directly
with the buff or protoxide recently precipi-
tated, and still remaining in the liquor; sim-
ple agitation in oxygenous gas or common air
for a few minutes, is all that is requisite. Or
it may be instantly formed by treating the
same moist protoxide with liquid oxyttiuriate
of lime. Or it may be had by exposing the
purest black oxide to a bright red heat for some
time, when it will lose 9 or 10 per cent, and
there will remain the olive brown oxide.
To find the proportion of oxygen absorbed,
I precipitated 3.2 grains of the protoxide by
lime water; the liquid containing the oxide
was put into a well stoppered bottle of oxygen
gas; on agitation the oxide changed colour
fast, from buff to brown; in a short time it
absorbed 260 grain measures of gas =.35 of
a grain in weight, and then ceased to absorb.
In another experiment, 3.2 grains of preci-
pitated protoxide/ took 100 measures of a
solution of Oxymuriate of lime, containing
.35 per cent, of oxygen, (that is, 1.45 oxy-
muriatic &cid). Hence as 32 take 3.5, 64
m^ttake 7; \vhieh shews the brown oxide to
■ - ( ' ■■ i i ' ? • .
METALLIC OXIDES. 77
be a compound of 1 atom of oxygen, and
2 of the protoxide.
The characters of this oxide are, its olive
brown colour, its insolubility in nitric and sul-
phuric acids, without heat or deoxidation, and
its solubility in muriatic acid after the evolu-
tion of oxy muriatic acid. By long exposure
to the air, it is gradually changed, in all pro-
bability into the black oxide.
3. Deutoxide. In order to determine the
quantity of oxygen deducible from the purest
native oxide of manganese, to convert it into
protoxide, I have successfully adopted the two
following methods. 1st. Let 39 or 40 grains
of the oxide be mixed with 60 common salt;
to this add 80 grains of water, and 120
grains weight of strong sulphuric acid, in a
gas bottle. The heat must be gradually raised
to boiling, and the oxymuriatic acid gas may
be received in a quart of lime water. This
will be found sufficient to convert 800 mea-
sures of test green sulphate of iron (1.156)
into red ; that is, it will produce 29 grains of
oxymuriatic acid, which will cause 7 grains
of oxygen, to unite to the green oxide of
iron. Now 100 measures of 1.156 sulphate*
according to some recent experiments of
mine, contain 8 grains of green oxide, (I es-
timated the sp. gr. of test sulphate, heretofore
78 METALLIC OXIDES.
at 1.149); hence 800 contain 64 oxide, and
these require just 7 grains of oxygen to be
united to them, to form the red oxide, as has
been shewn, page 34. In the above experi-
ment, the 39 grains of oxide, will be found
to vanish or be dissolved, if pure, and to
yield 32 grains of protoxide, making up with
the 7 grains of oxygen, the original weight.
Hence we have 39 grains of the oxide re-
solved into 32 protoxide, and 7 oxygen. If
then we allow 32 protoxide, to contain 7
oxygen, it appears that 39 grains of the na-
tive oxide, consists of 1 atom manganese
(25), and two atoms of oxygen (14); or
it is the deutoxide of the metal. 2d. A
more direct and expeditious method, of
transferring the oxygen from the manga-
nese to the iron, is as follows: Let 39 grains
of pure grey shining oxide, be mixed with
800 of test green sulphate of iron; to this
mixture let 25 or 30 grain measures of strong
sulphuric acid be added: after stirring the
mixture for 5 minutes, the oxide of manga-
nese will be completely dissolved, and, on
precipitating the oxide of iron gradually, by
lime water, it will be found to be wholly yeU
lowor buff; shewing that 7 grains of oxygen
have been transferred from the oxide of man-
ganese to that of iron. — If more green suU
METALLIC OXIDES. 79
phate of iron be used, then the surplus of
the oxide will be thrown down green; the
order of precipitation being the yellow oxide
of iron, the green oxide of iron, and lastly,
the yellow or buff oxide of manganese, as
has been stated. This affords an easy and
elegant method of appreciating the different
oxides of manganese of commerce; and it
was in this mode, the valuations of the spe-
cimens in the above table were made.
The proportions of the three oxides are
then as under :
r ■•
Manganese Oxygen
Protoxide 100 + 28 — buff; soluble in acids.
Intermediate oxide- -f- 42 — brown ; insoluble.
Deutoxide -{- 56 — black; insoluble.
It may be proper to subjoin the results of
others, who have investigated the oxides of
manganese. Bergman finds 3 oxides, con-
taining 100 metal + 25, 35, and 66.6 oxygen;
Dr. John finds 3 oxides, containing 100 me-
tal + 15, 25, and 40 oxygen: Berzelius finds
5 oxides, containing 100 metal + 7, 14, 28,
42, and 56 oxygen ; and Davy finds 2 oxides,
containing 100 metal + 26.6, and 39.9 oxy-
gen, respectively.
80 METALLIC OXIDES.
23, Oxides of chromium.
There appear to be at least two oxides of
chromium, one or other of which is found in
combj^atiqn with the oxides of lead or iron,
but hithertpj so dtiffljfi sparingly that few che-;
mists have had an opportunity of investigating
the proportions of chrome and oxygen, in the
oxides of chromium. The chief sources for
information on this subject, ( are essays by
Vauquelin, An. de Chimie, Vol. 25 and, 70;
by Tassaert, ibid. 31; by Mussin Puschin,
ibid. 32; by Godon, ibid. 53; by Laugier
ibid. ,78, and by Berzelius, Annal. of Philo-
sophy, 3.
The oxides of chromium, as might be sup-
posed, are distinguished for the colours which
they possess and impart to the compounds
into which they enter. One of the oxides is
green; it gives colour to the emerald. The
other is yellow, dissolved in water, but deep
red when crystallized, and possesses the cha-
racters of an acid; it unites with alkalies,
earths, and metallic oxides; it was first found
in Siberia, in combination with the oxide of
lead, a salt now denominated chromate of
lead, of a splendid yellow colour, inclining
to orange or red. Since then, the chromate
METALLIC OXIDES. 81
of iron, has been found in France, America,
and Siberia, with a prospect of greater abun-
dance.
In order to investigate the weight of the
atom of chromic acid, it is necessary to at-
tend to such of the chromates as have been
carefully examined. The chromates of pot-
ash, barytes, lead, iron, and mercury, are
those with which we are best acquainted.
Vauquelin has given us the components of
the native chromate of lead by analysis, and
those of the artificial chromate by synthesis;
the results do not accord very nearly : for, ac-
cording to the analysis corrected by the mo-
dern science,
Chromate of lead = 62 acid -j- 97 oxide
By synth. chromate of lead e= 57| 1- 97 — —
Berzelius however, has more lately given
us the results of his experience, both analy-
tical, and synthetical; and he finds both to
give chromate of lead nearly = 44 acid 4- 97
oxide.
Chromate of barytes (Vauq.)=47.8 acid ~f- 68 barytes
Ditto (Berz.)=44 |-SS
Native chromate of iron (Vauq.)=45 acid 4-351 oxide
Ditto. (Laugier)=55 h35|
VOL. II. L
82 METALLIC OXIDES.
Having* received a small portion of chro-
mate of potash in solution, from a chemical
friend (J. Sims), I endeavoured to satisfy
myself, as far as my materials would go, as
to the nature and proportions of the chro-
mates. The solution was of the sp. gr. 1.061,
and consequently in 100 measures contained
nearly 6.7 grains of chromic acid and pot-
ash, &c- — The liquid was a beautiful yellow;
it was alkaline by the colour test. By the
usual tests, I had reason to believe, that the
solution contained as under per cent. —
namely,
2.2 gr. chromic acid
2. potash
.8 uncomb. potash
1.4 carb. potash
.3 sulphate of potash
6.7
...
With this liquid neutralized by nitric acidf
I formed the chromates of lead, barytes, iron,
and mercury ; and I am inclined to believe
these salts are nearly constituted as under :
Neutral chromate of potash 46 acid -f- 42 potash
of barytes 46 \- 68 barytes
— of lead 46 (- 97 oxide
— of iron 46 ) «-f- 32 oxide (black)
1 of mercury 46 p-174 oxide (black)
METALLIC OXIDES. 83
According to these results, the atom of
chromic acid weighs 46; it is made 44 by the
results of Berzelius, and from 45 to 62 by
those of Vauquelin; I would not be under-
stood to place great confidence in the above
results of mine, though I am persuaded they
will be found good approximations.
Is the chromic acid the deutoxide, or the
tritoxideof chromium?
The determination will evidently be affec-
ted by the question, how much oxygen must
be abstracted from the chromic acid to reduce
it to the green oxide. Vauquelin finds 46
acid to lose 6| oxygen, and Berzelius lOf ,
when converted into green oxide by heat.
From the former of these, one would infer
chrome to be 32, the green or protoxide of
chrome to be 39, and the acid or deutoxide
46: from the latter, chrome = 25, protoxide
= 32 (unknown), the green oxide = 1 prot-
oxide and 1 deutoxide united [= 71 = 50
chrome -f 21 oxygen = (25 chrome + lOf oxy-
gen) x 2= 35f x 2] the deutoxide = 39, and
the tritoxide or chromic acid = 46. I have
not had an opportunity to perform any expe-
riment that appears to me decisive as to the
accuracy of one or other of these views ; but
shall make a few remarks relative to them.
84 METALLIC OXIDES.
The green oxide being- the most prominent
compound next to the chromic acid, being
commonly produced from it by any deoxi-
dizing process, being- the lowest oxide known?
and combining- with acids, is on these ac-
counts entitled to the consideration of the
protoxide; indeed there does not seem an in-
stance where the protoxide of a metal is un-
known, whilst the deutoxide and compound
oxides are known. There is however, ano-
ther oxide observed by Vauquelin and by
Berzelius, which is obtained by heating the
nitrate, or combination of nitric acid and the
green oxide, to dryness and expelling the acid ;
this oxide is brown, and gives oxymuriatic
acid when treated with muriatic acid ; on
this account it would seem to be interme-
diate between the green oxide and the chro-
mic acid; ^t is prohably a combination of the
two, or the chr ornate of chromium. On the
other view however, it must be considered as
the deutoxide. What corroborates the notion
of the green oxide being 39, is the fact which
I have observed, of 46 parts of chromic acid
combining with 64 of the green oxide of
iron to form 110 of chrotnate of iron ; in this
combination the oxide of iron may be said to
borrow 1 atom of oxygen from the chromic
METALLIC OXIDES. 85
acid, and the compound may then be consi-
dered as the union of the green oxide of
chrome, and the red oxide of iron. When
this precipitate is subjected to the action of
muriatic acid, a green solution is obtained
containing- the oxide of chrome, and red oxide
of iron is precipitated, as Vauquelin has ob-
served. To form the above chromate (or ra-
ther subchromate) of iron, let a given portion
of neutral chromate of potash be treated with
green sulphate of iron, and lime-water be
added, sufficient to saturate the sulphuric
acid, a brown red precipitate is obtained;
more sulphate and lime water must be gradu-
ally added to the clear liquid till the precipi-
tate become green, when the proportions will
be found as above stated. This artificial
compound seems a subchromate; whereas the
native compound seems to be a chromate.
That there is some uncertainty in decompos-
ing a chromate by heat with a view to obtain
the green oxide, I have reason to suspect from
having decomposed 54- grains of chromate of
mercury by a moderate red heat; this com-
pound contained 1.1 chromic acid, and it
'yielded only .6 of green oxide, whereas it
should have been .9 or .8 at least.
Upon the whole I think the evidence is in
favour of the opinion that the atom of chrome
86 METALLIC OXIDES.
is 32, the green or protoxide 39, and the
deutoxide or chromic acid is 46.
24. Oxides of uranium.
There appear to be two oxides of uranium
from the experiments of Klaproth, Bucholz,
and Vauquelin ; but the proportions of metal
and oxygen have not been very nearly ascer-
tained, from the great scarcity of the mine-
rals containing this metal. (Vid. Bucholz,
An. de Chimie, 56 — 142. Vauquelin, ibid. 68
—277; or Nicholson's Journ. 25— 69). The
oxides are obtained by precipitation from so-
lutions of the minerals in the nitric or muria-
tic acid, the foreign substances being first se-
parated.
The protoxide of uranium precipitates
dark bottle green by caustic alkalies, and
forms crystallizable salts with acids; the other,
probably the deutoxide, precipitates orange
yellow, and forms un crystallizable salts with
acids; in these respects the oxides bear a near
resemblance to those of iron.
Bucholz estimates the yellow oxide at 100
metal + from 25 to 32 oxygen; as it yields
oxymuriatic acid when treated with muriatic,
it is most likely to be the deutoxide; now if
METALLIC OXIDES. 87
we take 28 for the oxygen combined with 100
metal, the protoxide must consist of 100 me-
tal + 14 oxygen, or of 50 metal + 7 oxygen,
and the atom of uranium = 50. From his ac-
count of the sulphate and nitrate of uranium
the weight of the atom might be inferred to
be double of the above or 100a These diffe-
rent conclusions can only be elucidated by fu-
ture experiments.
25. Oxides of molybdenum.
The latest and as it should seem most ac-
curate experiments on the oxides of molybde-
num were made by Bucholz. (Vid. Nichol-
son's Journal, 20, p. 121). There appear to
be 3 oxides or combinations of molybdenum
and oxygen, namely, the brown, the blue, and
the white or yellow. The two last have the
character of acids, and none of them seem to
form salts with acids, like oxides in general.
Bucholz ascertained the above gradation,
and that the white oxide or molybdic acid con-
tains 4- of its weight of oxygen; (which has
since been corroborated by Berzelius) ; he also
found that the blue was best formed by mixing,
triturating, and boiling in water 3 parts of
brown oxide, and 4 of white, or one of me-
tal, and two of acid ; and that it has acid
88 METALLIC OXIDES.
qualities as well as the white. Bucholz also
found 3 parts of liquid ammonia of the sp. gr.
.97 dissolve 1 of molybdic acid; now 3 parts;
of ammonia— .186 real (Vol. 1, p. 422);
and 1:. 186:: 64-: 12, the quantity of ammo-
nia usually saturated by one atom of acid;
and Berzelius found 100 molybdic acid
saturate 155 oxide of lead, or 63 acid to 07
oxide. The native sulphuret of molybdenum
(the state in which this metal is usually found)
was analyzed by Bucholz and found to consist
of 60 metal and 40 sulphur.
The molybdic acid may be obtained by
roasting the sulphuret in a crucible and stir-
ring" it frequently; the sulphur in great part
escapes in the form of sulphurous acid and
the metal becomes oxidated: carbonate of
soda in solution may be added to the residuum
as long as any effervescence is observed; mo-
lybdate of soda remains in solution and the
acid may be precipitated by nitric acid. The
brown oxide is best obtained by heating mo-
lybdate of ammonia to red; the ammonia and
part of the oxygen are expelled, and the
brown oxide remains.
There are two views with which the pre-
ceding results may be reconciled; namely, 1st.
supposing the atom of molybdenum to weigh
21 ; and 2d, by supposing it to weigh 42 or
METALLIC OXIDES. 89
twice that number. In the first case the
brown oxide will weigh 24| (49) being* sup-
posed 2 atoms of metal and 1 of oxygen, the
blue or protoxide will weigh 28, and the
white oxide or molybdic acid will weigh 63,
being a compound of the protoxide and deut-
oxide, molybdena or native sulphuret will then
be as usual, the protosulphuret, consisting of
21 metal and 14 sulphur, or 60 metal and 40
sulphur. In the 2d. case the brown or prot-
oxide will weigh 49, the blue or deutoxide
56, and the acid or tritoxide 63. The na-
tive sulphuret, molybdena, must in this view
be the deutosulphuret, or 42 metal and 28
sulphur.
The former of these views exhibits the ox*
ides somewhat complicated, but agrees well
with the sulphuret; the latter shews the oxides
in a more regularirain, but does not appear so
probable from the sulphuret; besides, the no-
tion of a metallic tritoxide is rather singular,
especially in a metal that is rarely if ever
found in combination with oxygen. Upon
the whole I prefer the former view ; but it
must be considered as problematical only,
The atom of 60 (see page 267 Vol. 1) must
doubtless be erroneous.
VOL. II. M
90 METALLIC OXIDES.
26. Oxides of tungsten.
From the experiments of D'Elhuiarts, Bu-
cholz* and Berzeliusf it seems very probable
that the tungstic acid is composed of about
100 metal + 25 oxygen. It is a yellow pow-
der of the sp. gr. 6.12, and is best obtained
from the native tungstate of lime (a scarce
mineral). One part tungstate of lime and
four of carbonate of potash are fused together,
dissolved in water, and then the tungstic acid
may be precipitated by nitric acid. There is
an inferior oxide that is black or dark brown ;
Berzelius reduced the yellow oxide to a flea-
brown colour, by sending a current of hy-
drogen gas through it in a glass tube heated
red hot. 100 parts of this oxide burnt be-
107 yellow oxide. Hence 100 metal must
combine with about 16| or 17 oxygen to form
this oxide, which is |> of that in the yellow
or tungstic acid. — Upon the whole it does
not seem improbable, considering the great
sp. gravity of this metal, that it forms three
oxides and that the acid or yellow oxide is
* An. of Philos. 6—198
fAn. of Philos. 3—244
METALLIC OXIDES 91
the 3d. Hence the atom of tungsten must
be 84, that of the protoxide 91, the deutox-
ide 98, and the tritoxide or tungstic acid 105.
The native tungstate of lime, if pure, ac-
cording to this would be 81.4 acid +18.6 lime,
which is not far from Klaproth's analysis ; he
having found 18.7 lime in one specimen; nor
from that of Berzelius, he having found
80.4 tungstic acid and 19.4 lime in 99.8
tungstate of lime.*
There is another view however, which
would accord with the experiments and per-
haps will be found preferable in other res-
pects; that is, to suppose the tungstic acid to
be composed of 1 atom deutoxide and 1
atom protoxide united ; in this case the atom
of tungsten = 42, that of the protoxide = 49,
that of the deutoxide # 56, and the tungstic
acid = 105 as before.
27. Oxides of titanium.
Nothing certain is known respecting the
oxides of titanium. An observation of Rich-
ter, quoted by Berzelius (An. of Philos.
3—251), if it could be relied upon, furnishes
an important fact, namely, that a solution of
*An. of Philos. 8—237
92 METALLIC OXIDES.
muriate of titanium containing' 84.4 oxide,
gave 150 muriate of silver. Now 150 muri-
ate of silver contain 28 acid ; hence 28 acid
must have combined with 84.4 oxide ) but if
28 : 84.4 :: 22 : 66 nearly for the weight of an
atom of the oxide. This would indicate 59
for an atom of the metal.
2 8 . Oxides of columbium .
The white oxide or acid of columbium is
found in combination with the oxides of iron
and manganese in proportion nearly as 4 of
the acid to 1 of the aggregate oxides. The
two minerals, columbiteand tantalite, though
yielding these substances nearly in the same
proportions, are found to differ remarkably in
specific gravity, the former being about 5.9
and the latter about 7.9. Dr. Wollaston
concludes however, from the agreement of
the white oxides extracted, that they must be
the same. The white oxide of columbium
is insoluble in the mineral acids; it unites
with potash by fusion, and may be precipi-
tated by most acids. Some of the vegeta-
ble acids, the oxalic, the tartaric, and the
citric dissolve the white oxide. When the
alkaline solution of columbium previously
neutralized by an acid is treated with infusion
METALLIC OXIDES. 93
of galls, an orange precipitate is produced
which is characteristic of columbium. No-
thing certain has been determined respecting
the proportions of metal and oxygen; but
from the great proportion of the columbic
acid found with the oxides of iron and man-
ganese, together with the great sp. gravity of
the compound, one may pretty clearly infer
the great weight of the atom of columbium.
Supposing the white oxide or acid to consist
of 1 atom metal 4- 3 oxygen and that the co-
lumbite is formed by 1 atom of acid to 1 of
oxide, we should have 128 acid 4* 32 oxide.
This would give 107 for the weight of an atom
of metal, and 128 for that of the tritoxide
or columbic acid; but it is unnecessary to
dwell upon such conjectures.
In a recent memoir of Messrs. Gahn,
Berzelius, and Eggertz (An. de Chimie,
Octo. 1816), it is maintained as probable that
there is only one oxide of columbium or tanta-
lum, and that 100 metal take 5.485 oxygen,
or 121 metal take 7 oxygen. If this be cor-
rect, the atom of columbium must be 121 and
the protoxide 128.
(See also An. de Chimie, 43 — 271 ; Philos.
Trans. 1802; Nichols. Journ. 2— 129; ibid.
3—251 ; ibid. 25—23).
94 METALLIC OXIDES.
29. Oxides of cerium.
The mineral cerite is of the sp. gr. 4.53,
and constituted of 50 or 60 per cent, of oxide
of cerium, with silex, lime, and iron. This mi-
being calcined and dissolved in nitro-muriatic
acid, the solution is to be neutralized by
caustic potash, and then treated with tar-
trate of potash. The precipitate, well washed
and afterwards calcined, is pure oxide of ce-
rium. • This oxide, which is white, when
calcined in the open air becomes red and ac-
quires more oxygen. These oxides, parti cu J
larly the white, are soluble in most acids;
the red oxide with muriatic acid gives oxy-
muriatic acid.
The experiments hitherto made on this sub-
ject scarcely enable us to decide respecting
the proportions of metal and oxygen, nor the
relative weights of these oxides.
Both Vauquelin* and Hisingerf agree that
the proto-carbonate of cerium, when expo-
sed to a red heat, yields 57 or 58 oxide,
which the former says is the red oxide, being
* An. de Chimie, 54—28
fAii.ofPhilos.— 4—356
METALLIC OXIDES. 95
changed by the calcination. Hisinger finds
the percarbonate to consist of 36.2 acid and
63.8 oxide : also that the muriate of cerium
consists of 100 acid and 197.5 oxide; but
Vauquelin remarks that the sulphate, nitrate,
and muriate of cerium are always more or
less acid, however dried; and he found the
protoxalate of cerium to yield 45.6 red oxide
by calcination, on a mean of 3 experiments
not much differing from each other. Sup-
posing all these facts accurate, they may be
reconciled by a few suppositions by no means
improbable. Let the atom of cerium be 22,
the protoxide 29, and the red oxide 32§ (that
is, 1 oxy. 4- 2 protox. =65)', and let the
protocarbonate be 1 atom of acid, 1 of oxide,
and 1 of water; the percarbonate, 1 acid 1
oxide; the oxalate, 1 acid (40) and 1 oxide;
and the muriate, saturated with base, 3 ox-
ide and 2 acid. Then it will be found that,
The decomposed protocarbonate will yield 57.5 red oxide;
The decomposed percarbonate will yield, 36.7 acid, 63.3
oxide;
The decomposed oxalate will yield 47 red oxide; and
The muriate will yield 100 acid (22), and 197.7 oxide.
All of which agree very nearly with the re-
sults above obtained.
96 SULPHURETS.
Hence it appears to me very probable that
the several atoms of the metal and the oxides
are as stated above; and that,
100 cerium + 31.8 oxygen = 131.8 protoxide, white
f- 47.7 — — ■ =• 147.7 intermediate, red.
Hisinger, from some of the same data uni-
ted to other hypothetical facts than those as-
sumed above, deduces the two oxides very
different; viz. 100 metal 4- 17.4 oxygen for
the protoxide, and 100 + 26.1 for the per-
oxide.
SECTION 14.
EARTHY, ALKALINE AND METALLIC
SULPHURETS.
The sulphurets exhibit a very important
class of combinations of two elements. Many
of the metals are found chiefly in the state of
native sulphurets, and are extracted by par-
ticular processes. Artificial combinations of
sulphur and the metals, and of sulphur and
the earths and alkalies are commonly prac-
tised, and are found useful in chemical inves-
SULPHURETS. 97
ligations. The alkaline and earthy sulphu-
rets will scarcely be allowed perhaps to be
combinations of two elements only ; but their
analogy with the other compounds is such as
to induce us to treat of them under this head,
especially as they are agents occasionally in
the formation of metallic sulphurets, and these
cannot be so well understood without some
knowledge of the other. For like reasons
the compounds of three elements, sulphur,
metal, and oxygen, called sulphuretted ox-
ides, and sulphuretted sulphites, and those of
four elements, sulphur, metal, oxygen and hy-
drogen, called hy drosulphurets, may be con-
sidered at the same time, having an intimate
relation with the sulphurets strictly so called,
or the compounds formed with sulphur and
the undecompounded bodies.
Sulphur may be combined with the earths,
alkalies and metals, by heat, of various de-
grees according to the nature of the subjects.
The union is attended in many cases with a
glowing ignition, indicating the evolution of
heat. The metallic oxides and sulphur when
heated together commonly produce a sulphu-
ret of the metal, whilst the oxygen escapes
with part of the redundant sulphur in the form
of sulphurous acid, and the rest of the sul-
phur sublimes.
VOL. II. K
98 SULPHURETS.
In the humid way sulphur may be combined
with earths, alkalies, and metals, by means of
sulphuretted hydrogen, hydrosulphurets (that
is, sulphuretted hydrogen united to other alka-
line or earthy bases), and hydroguretted sul-
phurets (a name given to certain earthy and
alkaline sulphurets formed mostly by boiling
mixtures of the respective bases and sulphur
in water.) The sulphuretted hydrogen may
be used in this state of gas or combined
with water; the hydrosulphurets and hydro-
guretted sulphurets are best applied in their
watery solutions. The metals are to be used
in this case in the state of salts, that is, ox-
ides united to acids, and in solution; or their
oxides may in some instances be precipitated
previously to the addition of the sulphur com-
pound ; the alkalies and earths are sometimes
directly sulphurized in the state of hydrates,
and at other times by double affinity, in the
state of salts or combined with acids. The
phenomena in the case of sulphurets formed
in the humid way, are various and often com-
plicated, and the true results are not always
to be obtained without considerable difficulty
and uncertainty.
tIME. 99
1. Sulphurets of lime.
When pounded liine and sulphur are mixed
together, and heated in a crucible scarcely any
union takes place; the sulphur sublimes or
burns away and leaves the lime unaltered. If
for lime we substitute carbonate of lime, it
also remains unaltered. But if hydrate of
lime and sulphur are heated together in equal
weights, the hydrate is decomposed, and the
lime unites to a portion of the sulphur, whilst
the excess of sulphur sublimes or burns and
escapes at a low red heat. The residue, about
60 per cent, of the original weight, is a yel-
lowish white powder, composed of sulphur
and lime. If this be again treated with sul-
phur and heated, it undergoes no material
change; the last sulphur entirely escaping,
leaves the sulphuret unaltered, and hence
shews that it must be a true chemical com-
pound.
Now if 32 parts hydrate of lime, which
consist of 24 lime and 8 water, be mixed with
32 sulphur and heated as above, they will
yield 38 parts sulphuret, which must be com-
posed of 24 lime and 14 sulphur, or sulphur
and water; but it appears from the analysis
100 SULPHURETS.
hereafter to be given, that the whole of this
last part is sulphur; therefore the compound is
formed of 1 atom of lime, and 1 of sulphur,
and is the protosulpkuret of lime.
When 32 parts of common hydrate of lime
and 56 sulphur, are boiled together in 1000
parts water for half an hour, or more, occasion-
ally adding water to supply the waste, a fine
yellow liquid is obtained, with a few grains
of residuum containing both lime and sulphur
nearly in the original proportion with a few
grains of alumine. This liquid of course
contains in solution, a combination of 1 atom
of lime, or perhaps hydrate of lime, and 4
atoms of sulphur ; and may therefore be called
a quadrisulphuret of lime. If more sulphur
or lime than the above proportion be used, the
surplus will remain in the residuum uncom-
bined, shewing that by this process no other
than a quadrisulphuret can be formed. A
similar solution may be obtained in cold water
by frequent agitation; bflt it is much slower
in producing the effect. The strength of li-
quid quadrisulphuret depends upon the relative
quantity of the ingredients. I have boiled it
down till the water was only 5 times the other
materials, which appears to be its maximum
strength in the common temperature; its spe-
LIME. 101
cific gravity was 1.146; but in general I have
used it of less than 1.07 density. It may
be proper to remark here that I find the decimals
multiplied by 4 express very nearly the num-
ber of grains of lime in 1000 grains measures
of the solution, and multiplied by 9 those of
the sulphur; on this account a solution of the
sp. gravity 1.06 facilitates the calculations, as
100 measures of it contain 2.4 grains of lime,
and 5.4 or 5.6 of sulphur nearly.
It is rather surprising that no bisulphuret
nor trisulphuret of lime should be formed this
way. One would suppose that the sul-
phuret of lime in its progressive changes
would have passed through the forms of bi-
sulphuret, &c. till it had obtained itsmaximum
of sulphur when that was in excess; but,
as has been observed, the quadrisulphuret is
the only one formed, whatever may be the
proportions of the ingredients. I imagine
the reason to be, that the sulphur has to de-
compose the hydrate of lime, and that no
fewer than 4 atoms of sulphur are adequate
to that effect; it is known that water adheres
so strongly to lime as to require a red heat to
separate it. When therefore we mix lime
water with quadrisulphuret of lime, it must
be considered as a mere mixture of the two,
and that the lime does not divide the sulphur
10£ SULPHURETS.
Equally. Consistently with this reasoning,
whenever the lime is in excess in forming qua-
drisulphuret of lime, we ought to consider
the liquid solution as lime watey holding qua-
drisulphuret of lime. This distinction will
be of some importance when the solution is
weak, because then the lime in the lime water
will be considerable, compared with the lime
combined with sulphur.
1. Protosulphuret. The properties of this
compound are; — about 1 grain is soluble in
1000 water; this water, as well as the powder
itself, tastes like the white of an egg; salts
of lead are thrown down black by the solu-
tion; weak nitric and muriatic acids dissolve
the lime, and leave the sulphur; 100 parts of
test acid require 19 of the powder, and yield
7 of sulphur; indicating the compound to be
12 lime and 7 sulphur. The same conclusion
may be obtained by means of a solution of
lead; if water containing 1.9 grains of the
powder be precipitated by nitrate of lead, it
will require 7 grains of the salt = 2.2 acid and
4.8 oxide, or 4.5 lead, and about 5 or 5 J
grains of sulphuret of lead will be formed,
and the liquid will contain 3.4 grains of neu-
tral nitrate of lime.
2. Quadrisulphuret. This combination has
been long known, and some of its properties
LIME. 103
observed; but I have not found in authors
any determination of its proportions. It is of
a beautiful yellow or orange colour, and 1
grain imparts very sensible colour to 1000 of
water; it has a disagreeable bitter taste;
when evaporated down, it crystallizes or ra*
ther perhaps solidifies into a yellowish mass;
but its properties are affected by the process
from the acquisition of oxygen. This mass
when dried, burns with a blue flame and loses
40 per cent. ; the remainder is a white powder,
a mixture of sulphite and protosulphuret of
lime. Liquid quadrisulphuret exposed to the
atmosphere soon becomes covered with a white
film which arises from the sulphur displaced by
oxygen gas; this film being broken subsides,
and another is formed, and so on successively
till at length the acquisition of oxygen ceases
with the deposition of sulphur, and the li-
quid remains quite colourless. It is intensely
bitter, and contains lime, sulphur and oxygen
in proportions to be presently determined.
This colourless liquor undergoes a gradual
change by being kept for years in a bottle
with a common cork ; a deposition of some
sulphur and sulphate of lime takes place, but
whether from a further acquisition of oxygen
gas or from some internal chemical action, I
have not had an opportunity of observing.
104 SULPHURETS.
From the above observations it is obvious
that to form pure quadrisulphuret of lime the
atmospheric air should be excluded, as the
agitation by ebullition would promote the oxi-
dizement of the compound. I mixed 168
grains of sublimed sulphur with 96 hydrate
of lime, which by previous trials I had found
to consist of 70 lime including1 2 or 3 grains
of alumine, and 26 water; the mixture was
put into a small florence flask, which was
then filled with water up to the neck and
loosely corked. This was immersed in a pan
of water and boiled for 2 or 3 hours, the
flask was continually turned round to agitate
the mixture and promote the solution. After
the undissolved part had subsided the clear
liquor was decanted an d found to be 2800 grain
measures of the sp. gr. 1.056; the residuum
moderately dried weighed 34 grains ; it was
found to contain 8 of lime and alumine, and
25 of sulphur. Hence the liquid contained
62 lime and 143 sulphur, or 2.2 lime and 5.1
sulphur per cent. ; that is, after the rate of
24 lime to 56 sulphur, or 1 atom of lime to
4 of sulphur, and its weight = 80, the atom of
sulphur being supposed 14. Here then we
have a synthetic proof of the composition be-
ing a quadrisulphuret. Innumerable other
experiments, though made with less rigid ac-
LIME. 105
curacy, had convinced me that the liquid is
essentially the same whatever the proportions
of the ingredients, and that the residuum only
varies in such cases.
I have made many experiments occasionally
since 1805, on the quantities of oxygen ab-
sorbed and sulphur deposited by quadrisulphu-
ret of lime. They all concur in establishing
the same conclusion ; namely, that each atom
of the compound takes 2 of oxygen and de-
posits 2 of sulphur, in its transformation from
the yellow to the colourless state. For in-
stance, 100 measures of the above 1.056 took
900 of oxygen gas == 1.22 grains, and let fall
2 grains of sulphur, besides a small portion
which adhered to the bottle, which was esti-
mated at a few tenths of a grain. The me-
thod is to put 100 measures into a graduated
and well stoppered bottle filled with oxygen;
to agitate briskly for half an hour, occasion-
ally opening the stopper a little under water
to admit its entrance into the place of the
oxygen absorbed. Whenever the agitation
has been continued for five minutes without any
sensible increase in absorption, and the liquor,
after standing to let the sulphur subside, ap-
pears colourless, the experiment is finished.
This new combination then consists of 1 atom
lime, 2 sulphur, and 2 oxygen = 66; it will
VOL. II. O
106 SULPHURETS.
be necessary to give it a name : I propose
calling* it sulphuretted sulphite of lime, as it
is an atom of sulphur united to sulphite of
lime; and the rather, as it will appear in the
sequel that other neutral salts do combine oc-
casionally with an atom of sulphur. This
sulphuretted sulphite may be boiled down to
the sp. gr. 1.1 before it precipitates: the li-
quid then contains about 12 per cent, of the
salt, or 5 sulphur, 2§ oxygen, and 4| lime.
The salt precipitates from the liquid by eva-
poration in the form of a white powder; it
burns with a feeble blue flame, and loses about
20 per cent. ; the remainder is sulphite of lime.
When 100 grain measures of the liquid sul-
phuretted sulphite (1.1) are saturated with
oxymuriate of lime, they acquire 5 grains of
oxygen, and then yield 12| grains of sulphu-
ric acid (containing 5 sulphur and 7{ oxygen),
as may be found by the barytic tests. The
point of saturation is known by the smell of
oxymuriatic acid being given out perma-
nently.
If however we oxidize the quadrisulphuret
of lime by oxymuriate of lime, the results are
somewhat different. As soon as an atom of
the quadrisulphuret has received two atoms of
oxygen it becomes colourless as before, but f
of the sulphur is thrown down instead of § ;
LIME.- 107
and when more oxyinuriate is added, so as to
impart 3 atoms of oxygen to one of the salt,
a complete sulphate of lime is formed. The
point of saturation is determined by adding a
small portion of muriatic acid to the liquid,
which developes the oxymuriatic acid as soon
as it becomes in excess. This method e eels
in the analysis of the alkaline and earthy
sulphurets in general.
When quadrisulphuret of lime is treated
with an alkaline carbonate, a reciprocal change
takes place; the carbonic acid takes the lime,
and the alkali the sulphur, leaving however
1 atom of sulphur with the carbonate which
precipitates. Hence a sulphuretted carbonate
of lime is obtained and a trisulphuret of the
alkali. The sulphur burns off from the car-
bonate below a red heat and leaves 75 per
cent, of carbonate of lime; this affords an
excellent analysis of quadrisulphuret of lime
as far as lime is the object. Thus 540 of the
above 1.056 quadrisulphuret took 100 test
carbonate of potash (1.25), and gave a pre-
cipitate of 29 grains, which burned blue and
left 22 grains = 12 lime, and 10 acid ; but if
540 : 12 :: 100: 2.2, as above determined
synthetically : moreover, 12 lime, 10 acid, and
7 sulphur, are as 24 lime, 20 acid, and 14
sulphur; the composition of an atom of sul-
108 SULPHURETS.
phuretted carbonate of lime, which is analo-
gous to the sulphuretted sulphite of lime, as
found above.
When quadrisulphuret of lime is treated
with as much sulphuric acid as is sufficient for
the lime, the sulphur is in part precipitated,
but it is in union with the sulphate of lime,
or at least they are not separable by mechani-
cal means. This compound is sold in the
shops under the name of precipitated sulphur.
It is about one half sulphate of lime, and
the other half sulphur. The nitric and mu-
riatic acids precipitate the sulphur partially
from quadrisulphuret, but the sulphur assumes
a viscid form and exhales sulphuretted hydro-
gen, and the proportion of the elements of
quadrisulphuret are not easily obtained by any
of these acids.
The mutual action of quadrisulphuret of
lime, and the metallic salts is curious and in-
teresting ; for instance, with nitrate of lead.
Let a solution of nitrate of lead, containing
97 oxide, be treated with a solution of qua-
drisulphuret of lime by degrees, as long as
a black precipitate appears, marking the ex*
act point of saturation ; this will be found when
36 parts of lime have entered, and 84 of sul-
phur; the sulphuret of lead will fall, and
When dried will weigh 145 parts, and contain
LIME. 109
90 lead, and 55 sulphur ; that is, 1 atom of
lead, and 4 of sulphur, and is consequently
a quadrisulphuret of lead. The liquid re-
mains clear and colourless, and contains the
nitric acid, lime, oxygen of the lead, and -^
of the sulphur ; each atom of nitric acid com-
bines with one of lime, which retains one
of the 4 atoms of sulphur, forming a sul-
phuretted nitrate of lime, consisting of 45
acid, 24 lime, and 14 sulphur; the 7 parts
of oxygen unite with 7 of sulphur to form
sulphurous acid, which require 12 parts of
lime to saturate them and 7 of sulphur, form-
ing a sulphuretted sulphite of lime : hence
we see that 28 parts of sulphur remain in the
liquor, and the rest (56) unite with the lead.
If now we add gradually more nitrate of lead,
a silvery white precipitate appears, increasing
till half the original quantity is added, and
then the liquid is saturated. This white pre-
cipitate is sulphuretted sulphite of lead; when
heated it soon grows black and loses 15 or 20
percent., being then a protosulphuretof lead.
The liquid now contains sulphuretted nitrate
and simple nitrate of lime; nitrate of lead
has no effect, but nitrate of mercury preci-
pitates a black sulphuret.
Quadrisulphuret of lime saturated with oxy-
gen, as has been observed, contains sulphu-
110 SULPHURETS.
retted sulphite of lime in solution, and de-
posits sulphur : the liquid treated with nitrate
of lead, gives as above the white, silvery sul-
phuretted sulphite of lead as a precipitate,
and holds nitrate of lime in solution.
Hydrosulphuret of lime. This compound
may be formed by passing sulphuretted hy-
drogen into lime water; the water assumes a
brownish colour, but the point of saturation
is not easily found, as the lime water is not neu-
tralized so as to shew by the colpur test,
and water of itself absorbs above twice its
volume of the gas. By means of a neutral
solution of nitrate of lead it may be found
that 1000 lime water in volume, require
about 600 sulphuretted hydrogen, because
then a mutual saturation is observed by dou-
ble affinity; that is, sulphuret of lead and
neutral nitrate of lime are formed; but other-
wise the liquid remaining is either acid or al-
kaline. Hydrosulphuret of lime, as well as
the other hydrosulphurets, has a peculiar bit-
ter taste. It forms a useful reagent in regard
to metals, but is apt to be spoiled by keeping?
owing to the acquisition of oxygen*
MAGNESIA. Ill
2. Sulphuret of magnesia,
I have not succeeded in endeavouring to
combine sulphur and magnesia in the dry
way ; but a liquid sulphuret is easily formed
by the action of double affinity.
Let a quantity of the liquid quadrisulphu-
ret of lime be treated with a solution of sul-
phate of magnesia, so that the sulphuric acid
may be sufficient for the lime; by digesting
in a moderate heat, the sulphate of lime is
precipitated, carrying with it one fourth of
the sulphur, and a trisulphuret of magnesia
remains in solution. I have not observed any
remarkable feature of distinction between this
sulphuret and that of lime, except as above
noticed in the proportions of their com-
pounds.
Hydrosulphuret of magnesia. This com-
pound may be formed by pouring sulphuret-
ted hydrogen water into recently precipitated
magnesia; it does not differ much from that,
of lime. One atom of sulphuretted hydro-
gen (15), combines with one of magnesia
(17), and the compound is soluble in water.
112 SULPHURETS.
3. Sulphur et of barytes.
Protosulphuret. The protosulphuret of ba-
rytes may be procured the same way as that
of lime, by heating hydrate of barytes and
sulphur till the mixture becomes red. It is
very little soluble in water, and accords in
other respects with the like compound of lime.
It consists of 68 barytes and 14 sulphur, or
100 barytes and 20| sulphur.
Quadrisulphuret. The quadrisulphuret of
barytes may be formed the same way as qua-
drisulphuret of lime, by boiling the hydrate
of barytes and sulphur together. A yellow
solution of the compound is formed, not dis-
tinguishable in appearance from that of lime ;
and it appears to be analogous to it in most of
its properties. By acquiring oxygen it be-
comes colourless sulphuretted sulphite of ba-
rytes, and crystalizes in needles; in this last
respect it differs from that of lime. The maxi-
mum density of liquid quadrisulphuret I have
not had an opportunity of ascertaining ; it is
1.07 or upwards; that of the liquid sulphuret-
ted sulphite is much less than that of lime ;
the crystals are found in a liquid so low as
1.004 sp. gr. They have a fine silky lustre
when dry, and a yellowish colour; heated
STRONTLTES. 113
they burn with a blue flame and leave a white
mass of sulphate preserving the same crystal-
line appearance as before, and lose about 20
per cent, of weight. Ten grains of the crys-
tals of sulphuretted sulphite, when treated
with liquid oxymuriate of lime to safuration,
require 2-f- grains of oxygen and yield 8 grains
of sulphate of barytes, together with an ex-
cess of sulphuric acid which with muriate
of barytes gives 8 grains more of sulphate.
From these facts it may be concluded that the
sulphuretted sulphite consists of one atom ba-
rytes, 2 sulphur, 2 oxygen, and 2 water,
and that 4 more of oxygen are derived from
the oxymuriatic acid to convert the sulphur-
ous oxide into sulphuric acid. The sulphu-
retted sulphite of barytes seems to pass into
sulphate by length of time. The weight of
the atom of quadrisulphuret of barytes is
124; the compound in mass consists of 100
barytes and 82 sulphur.
Hydrosulphuret of barytes. This com-
pound may be formed in the same manner as
that of lime, and is found to have similar
properties. The proportions for mutual sa-
turation are, I find, as in the case of lime, 15
sulphuretted hydrogen to 68 barytes by
weight, or one atom of each.
VOL. II. P
114 SULPHURETS.
4. Sulphurels of strontites.
The protosulphuret and quadrisulphuret of
strontites may be formed in the same way as
those of lime and barytes. From a few ex-
periments made on these compounds I have
not observed any remarkable feature of dis-
tinction between them and the correspond-
ing ones of the other earths.
Hydrosulphuret of strontites. This com-
pound may be formed in the same way as that
of lime; the proportions to produce mutual
saturation will be 1 atom of each, or 15
parts sulphuretted hydrogen, to 46 strontites
by weight.
5, 6*7, 8, and 9. Sulphur ets ofalumine, silex,
yttria, glucine, and zircone.
I made several unsuccessful attempts to
combine alumine and sulphur. When alu-
mine and sulphur mixed together are heated,
the sulphur sublimes chiefly, and leaves the
alumine with traces of sulphate of alumine.
In the humid way, recently precipitated
and moist alumine mixed with sulphur and
POTASH. 115
boiled in water, give a liquid with some tra-
ces of sulphuric acid, but no sulphuret of
alumine; the sulphur and alumine both sub-
side, and when the sulphur is either sublimed
or burnt, the alumine remains much the same
as at first. When a solution of alum is
treated with sulphuret of lime, sulphate of
lime is precipitated along* with the greatest
part of the sulphur in a kind of feeble union
rather than mechanical mixture, it should
seem ; the alumine is at the same time pre-
cipitated probably in mechanical mixture;
there remain in solution a little sulphuret of
potash and sulphate of lime.
Sulphuret of silex is not known, I appre-
hend, to exist. When silicated potash in so-
lution is treated with quadrisulphnret of lime,
a copious dark brown or black precipitate in-
stantly appears; the liquid when filtered is
of a pale yellow colour, and seems to contain
about one half of the sulphur and potash,
whilst the other half is thrown down in
union with the lime and silex. This black
compound is probably 1 atom of lime, 2 of
sulphur, 2 of potash, and 2 of silex; it can-
not therefore be accounted a sulphuret of
silex.
Sulphurets of yttria, glucine% and zircone,
are as yet, I presume, unknown.
116 SUI/PHURETS.
10. Sulphurets of potash.
Potash has a strong affinity for sulphur
and unites with it in various ways and pro-
portions.
1st. In the dry way by heat. When either
pure potash or the carbonate (salt of tartar)
is heated in a covered crucible with sulphur,
a chemical union of the two principles takes
place. Eight parts of dried hydrate of pot-
ash unite to six or seven of sulphur: a heat of
4 or 500° of Fahrenheit is convenient for the
purpose. If the carbonate of potash be used*
then 12 parts dried in a low red heat will re-
quire 8 of sulphur for their complete satu-
ration : in this case a higher degree of heat is
requisite in order to expel the carbonic acid;
alow red heat seems sufficient from my trials.
When the heat does not exceed 3 or 400° a
partial union takes place; the carbonate of
potash, without losing any acid, unites to ^
of the sulphur, and the rest of the sulphur
remains uncombined; when intermediate de-
grees of heat are used, I have found the re-
sult a mixture of the pure sulphuret and the
carbonated sulphuret, with more or less of
sulphate of potash. A high degree of heat
and exposure to the atmosphere produces a
POTASH. 117
sulphate instead of a sulphuret. The sul-
phurets obtained this way are in fusion till
poured out and cooled ; they are of a liver
colour, and hence were formerly called livers
of sulphur. They are largely soluble in wa-
ter, and give a brownish yellow solution.
2d. In the humid way by solution. Pure
caustic potash in solution when boiled with
sulphur dissolves it largely, 42 parts of real
potash being saturated with about 56 of sul-
phur. If we boil a solution of carbonate of
potash with sulphur, for an hour or more,
a brown liquor is obtained, which consists of
60 parts carbonate of potash and 14 sulphur
in chemical union. — It has already been ob-
served that a trisulphuret of potash may be
obtained by double affinity from quadrisul-
phuret of lime and carbonate of potash, to-
gether with sulphuretted carbonate of lime.
From what has been stated we may infer at
least three varieties in the compounds of sul-
phur and potash, viz. 1
1st. Sulphuretted carbonate of potash, ^his
consists of 1 atom carbonate of potash (61)
with I atom of sulphur (14). Its analysis
may be effected as follows : the quantity of
carbonic acid may be found by the lime water
necessary to saturate it ; the potash may be
known from the quantity previously entering
118 SULPHURETS.
into the mixture; and the sulphur in the
same manner, or from the quantity of sul-
phuretted carbonate of lead that it forms. —
The sulphur may also be known, from the
quantity of oxygen it requires by means of
oxymuriate of lime to produce saturation ;
this I find to take place when the oxygen is
half the weight of the sulphur, or one atom
to one of sulphur ; it soon happens, that one
atom of sulphur deprives two others of their
oxygen, and sulphuric acid is formed whilst
the other two atoms of sulphur join the car-
bonate of lime and are precipitated along
with it. As it may frequently happen, that
the sulphuretted carbonate is mixed with
common carbonate of potash, the propor-
tions may be found by means of nitrate of
lead, which being cautiously dropped into
the solution, lets fall first the brown sulphu-
retted carbonate of lead, and then the com-
mon white carbonate of lead.
The sulphuretted carbonate of potash ab-
sorb oxygen and precipitates metals much
the same in appearance as the other sulphu-
rets; but essential distinctions are observable,
some of which are noticed above, and others
will appear in the sequel.
2 and 3. The irisulphuret and quadrisul~
phuret of potash so nearly resemble the qua-
AMMONIA. 119
drisulphuret of lime in their properties, as
not to require any additional remarks.
Hydrosulphuret of potash. This combina-
tion, when duly proportioned, consists of 15
parts sulphuretted hydrogen, and 42 potash
by weight, or one atom of each. It may be
formed by directly uniting* the two elements,
or by decomposing hydrosulphuret of lime by
carbonate of potash. Its properties agree
with those of the other hydrosulphurets.
11. Sulphur ets of soda.
I have repeated most of the experiments
on the sulphurization of potash with soda, and
have not found anyone remarkable feature of
distinction, besides those which arise from
the weights of the atoms.
1 . Sulphuretted carbonate of soda consists
of 1 atom of carbonate of soda united to 1
of sulphur ; or of 47 parts of the former and
14 of the latter.
2. Trisulphuret of soda consists of 1 atom
soda (28) and 3 of sulphur (42).
3. Quadrisulphuret of soda consists of 1
atom soda (28) and 4 atoms of sulphur (56).
Hydrosulphuret of soda. This compound
consists'of one atom of each of the elements,
120 SULPHURETS.
or 15 sulphuretted hydrogen, and 28 soda,
In other respects it agrees with hydrosulphu-
ret of potash.
12. Sulphuret of ammonia,
The best way which I have found of pro-
curing sulphuret of ammonia, is to treat qua-
drisuiphuret of lime with the carbonate of
ammonia as long as any precipitate takes
place ; the precipitate is sulphuretted carbo-
nate of lime, 3 atoms of sulphur to 1 of
carbonate of lime. The liquid is of a pale
yellow, and contains ammonia and sulphur
united in the ratio of 1 atom (of 6) to 1
of sulphur: it may therefore be denomi-
nated the protosulphuret of ammonia.
The carbonate of ammonia is best procur-
ed by heating the common subcarbonate of,
ammonia, first pulverized, in a temperature of
100° for half an hour, or exposing it for a
few days to the atmosphere. What remains
of the salt is almost without smell; it should
consist of 19 parts acid, 6 ammonia, and 8
water nearly : the ammonia is usually however
a small degree in excess.
Hydromlphuret of ammonia. This com-
pound may be formed in the dry state by com-
GOLD. 121
bining- the two gases of sulphuretted hydro-
gen and ammonia over mercury; it is of a
white crystalline appearance, and very solu-
ble in water, and forms a fuming liquor of a
very pungent smell. It may also be obtained
by passing sulphuretted hydrogen into a ves-
sel containing liquid ammonia. I find about
110 or 120 measures of sulphuretted hydrogen
require 100 of ammoniacal gas. Hence it is
1 atom of sulphuretted hydrogen (15), that
unites to 1 of ammonia (6).
13. Sulphurets of gold.
There exist at least two sulphurets of gold,
the nature and proportions of which are ea-
sily ascertained \ though several authors as-
sert that no combinations of gold and sul-
phur are known; amongst these it is surpriz-
ing to find Proust : indeed most of the others
have probably been led by his authority to
adopt the opinion without examination. It is
not very easy to account for his deception.
Obercampf, in the Annal. de Chimie,
torn. 80. 1811, is the first author I have seen
who distinctly maintains the existence of one
or more sulphurets of gold, though it seems
to have been admitted previously by Bucholz.
The last author finds 82 gold unite to 18 sul-
phur, and the former 80 to 20 nearly.
vol. it. a
122 SULPHURETS.
Prolosulphuret of gold. This compound is
formed whenever a solution of muriate of
gold is agitated with sulphuretted hydrogen
gas, or with the same united to a base, as
lime or alkali. A black or deep brown pow-
der falls down by the addition of more gas,
till the whole of the gold is precipitated.
The oxide of gold loses one atom of oxygen,
and receives one of sulphur in its place,
whilst the hydrogen of the gas is carried off
along with the oxygen of the oxide. The
sulphuret dried and heated, burns with a blue
flame, leaving the gold nearly pure. This
compound consists, I find, of 81 gold and 19
sulphur per cent.; or 100 gold unite to 23
sulphur.
Trisulphuret of gold. This compound is
obtained whenever quadrisulphuret of lime
is gradually dropped into a solution of mu-
riate of gold ; it is a black powder, not quite
so deep as the former. Care must be taken
to saturate the excess of acid previously by
lime-water, to prevent any uncombined sul-
phur precipitating. Trisulphuret of gold be-
ing heated, burns with a blue flame, and leaves
the gold nearly pure; it loses from 40 to 45
per cent, by the process. It is constituted
of 1 atom gold and 3 sulphur, or 60 gold
PLATINA. 123
and 42 sulphur, nearly ; or 100 gold combine
with 70 sulphur.
From several experiments I am led to con-
clude that each atom of oxide of gold takes
3 of sulphur, and parts with 1 of oxygen to
the remaining sulphur; thus a trisulphuret of
gold is formed, and an oxide of sulphur ; the
liquid, being afterwards treated withoxymu-
riate of lime, is found to require twice the
oxygen of the gold for its saturation, when
a corresponding portion of sulphuric acid may
be precipitated by muriate of barytes.
14. Stdplmret of platina.
Sulphur may be combined with platina in
several ways, and probably in different pro-
portions; but the combination is not so easily
and elegantly effected as with many other me-
tals, and hence some uncertainty still remains
on the subject.
When a salt of platina is treated with sul-
phuret or hydrosulphuret of lime, or sulphu-
retted hydrogen water, the liquid slowly and
gradually grows dark brown and finally black ;
after agitation and standing a few hours, the
liquid is semitransparent, and a black floccu-
lent precipitate appears at the bottom . Some-
times after violent agitation, the liquid on stand-
ing a few minutes becomes a transparent brown ,
124 SULPHURETS.
but soon grows turbid again. In the course
of a few days, and by occasional agitation,
the liquid finally becomes clear and nearly free
from platina, and the precipitate may be col-
lected on a filter and dried. This circum-
stance of slow and indolent precipitatiou can-
not be prevented by any means I have found,
such as saturating the excess of acid, &c.
Mr. Edmund Davy, in the 40th Vol. of the
Philos. Magazine, has given us the results of
his experiments and observations on the sul-
phurets of platina, containing some useful and
original information. He combines platina
with sulphur by heating the ammonia-muriate
of platina with sulphur; also by heating1 pla-
tina and sulphur in an exhausted tube; and
by sending sulphuretted hydrogen gas or wa-
ter into a solution of muriate of platina; this
precipitate he calls hydrosulphuret of platina.
He has just noticed the precipitate formed
by sulphuret of potash with muriate of pla-
tina, but gives no opinion as to the compound
obtained this way. He determines three sul-
phurets, namely,
Subsulphuret, 100 platina + 19 sulphur
Sulphuret, 100 -f 28.2
Supersulphuret, 100 -f 38.8
I have obtained the sulphuret of platina in
five ways : 1st. By pouring sulphuret of lime
PLATINA. 125
solution by degrees into muriate of platina,
and agitating the mixture well or till it grew
black each time; after digesting for some
days, repeated filtering, and drying, a black
powder is obtained: 2. Instead of suiphuret,
hydrosulphuret of lime was used; the preci-
pitate was obtained under like circumstances :
3d. Sulphuretted hydrogen water was used,
and the precipitate obtained in like manner :
4th. Ten grains of ammonia-muriate of pla-
tina were treated with sulphuretted hydro-
gen water; by, continued agitation the yellow
powder disappeared, the liquid looked uni-
formly black, and at length a precipitate was
formed; by ^repeated filtration and addition
of sulphuretted hydrogen water, the whole
of the platina was thrown down, and the
liquid remained colourless; but it is difficult
to discover the exact quantity of sulphuretted
hydrogen requisite for any weight of the am-
monia-muriate from the tediousness of the
operation; 6 grains of well dried black pow-
der were obtained, besides perhaps 1 grain
of loss on the filters: 5th. Ammonia-muriate
of platina was heated in a covered crucible
along with sulphur till it was judged that all
the uncombined sulphur was sublimed or dis-
sipated.
All these sulphurets appear to me to be the
126 SULPHURETS.
same when dried in a moderate heat. When
exposed to a low red heat they yield water and
sulphurous acid, and lose about £ of their
weight.
The subject however, requires further in-
vestigation. The sulphurets of platina ap-
pear of a complex nature, and the propor-
tions of their elements are not yet determined
with precision.
15. Sutyhurets of silver.
Silver combines with sulphur in two diffe-
rent proportions, and forms two sulphurets,
both of them black or dark brown.
1. Protosidphuret of silver. This may be
formed either by the dry or humid way : if
thin lamina of silver be heated with sulphur,
they combine and form this sulphuret; a
higher degree of heat expels the sulphur again.
It is formed too by passing sulphuretted hy-
drogen or a hydrosulphuret through a solu-
tion of silver in nitric or other acids. The
atom of silver unites with that of sulphur,
whilst the hydrogen unites with the oxygen.
Of course this compound is composed of 90
silver, and 14 sulphur, and the atom weighs
104; or 100 silver unite with 15.5 sulphur.
Klaproth finds 100 silver and 17.6 sulphur;
Wenzel 100 silver, and 14.7 sulphur; Ber-
MERCURY. 127
zelius 100 silver, and 14.9 sulphur \ and Vau-
quelin 100 silver, and 14 sulphur.
Trisulphuret of silver. This compound
is formed whenever neutral nitrate of silver
is dropped into a solution of quadrisulphuret
of lime or alkali. Mutual saturation seems
to take place when eight atoms of nitrate
meet with seven of quadrisulphuret. Tri-
sulphuret of silver is constituted of 90 silver,
and 42 sulphur; orof 100 silver, and 46.5 sul-
phur. Its colour is not so dark as that of the
protosulphuret. The residuary liquid con-
tains sulphurous acid, which is easily con-
verted into sulphuric by the addition of a por-
tion of lime; and the quantity of acid may
then be determined by muriate of barytes.
16. Sulphur ets of mercury.
Mercury combines readily with sulphur
both in the dry and humid way, and that in
several proportions, as under: namely,
1. Protosulphuret of mercury . This is most
conveniently formed by passing sulphuretted
hydrogen gas through a solution of the pro-
tonitrateof mercury, or by pouring hydrosul-
phuret of lime, &c. into the same solution.
The protosulphuret falls down in the state of
a black powder. • It consists of 167 mercury,
128 SITLPHURETS.
and 14 sulphur; or of 100 mercury, and 8.4
sulphur. The theory of its formation is the
same 'as' that of silver.
2. Deutosulphuret of 'mercury. This is form-
ed in the humid way whenever sulphuretted
hydrogen or ahydrosulphuret in excess is mix-
ed with the deutonitrate or deutomuriate of
mercury (corrosive sublimate) ; a brown pow-
der is precipitated which is the deutosulphu-
ret. If the sulphuretted hydrogen be only one
half what is sufficient to form the deutosul-
phuret, then we obtain no sulphuret, but in-
stead of it a protonitrate or protomuriate, as
was first intimated by Proust ; I find however,
the atom of sulphur adheres to the atom of
salt, and that it is therefore a sulphuretted
protonitrate or muriate, whilst 1 atom of
oxygen unites with the hydrogen. The brown
precipitate does not change to yellow, orange,
and red, when left undisturbed for a few days,
in my experience; though this is stated to
have been observed by Mr. Accum. Not-
withstanding the difference in colour, this
deutosulphuret must be the same nearly as the
cinnabar and Vermillion of commerce, if
Proust and others are right in their analysis
of thes« articles. The combination of the ele-
ments of sulphur and mercury when intended
to form cinnabar is made in the dry way by tri-
MERCURY. 129
turation, and a moderate heat; the compound,
at first black, is afterwards sublimed by a
duly regulated heat and becomes red. This
compound must consist of 100 mercury and 17
sulphur nearly.
3. Quadrisulphuret of mercury. This com-
pound is formed when a solution of protoni-
trate of mercury is treated with quadrisulphu-
ret of lime, added by degrees till the clear
liquid no longer gives a dark coloured precipi-
tate. The oxygen of the mercurial salt unites,
it should seem, to part of the sulphur, and
forms sulphuric acid, whilst the rest of the
sulphur unites to the mercury. This sulphuret
is a black or dark brown powder, and when
heated burns with a blue flame. It consists of
100 mercury, and 33 or 34 sulphur, as ap-
pears to me from the synthesis.
When the insoluble muriate of mercury
(calomel), is triturated in liquid quadrisul-
phuret of lime, it is soon decomposed ; qua-
drisulphuret of mercury is formed, with mu-
riate of lime and sulphuric or sulphurous
acid.
When the soluble muriate (corrosive subli-
mate), has quadrisulphuret of lime dropped
into it by degrees ; at first a yellowish white
precipitate is obtained, which increases till
it is one half saturated \ after this, by conti-
VOL. II. R
130 SULPHURETS.
nually adding" more sulphuret, the precipitate
grows darker, and ends in being1 quite black.
It is at least as high as quadrisulphuret. Much
sulphurous acid is found in the liquid.
The deutonitrate of mercury, produces a
copious yellow precipitate with quadrisul-
phuret of lime. Exposed to the sun, it
grows black in a few minutes on the light
side, but continues yellow on the opposite
side of the jar; at the same time, an effer-
vescence and disengagement of oxygen gas
are observed. Finally, the precipitate be-
comes the common quadrisulphuret, and the
liquid contains sulphurous and sulphuric acids.
The recently precipitated and washed ox-
ides of mercury act upon quadrisulphuret of
lime. The black oxide seems to take 4
atoms of sulphur and part with its oxygen to
another portion of sulphur; but the red oxide
becomes light brown and retains the colour
when dried. It seems to take the same sul-
phur as the black, but whether it retains any
of the oxygen, I have not ascertained. The
action is more slow than when the nitrates are
used, and more quadrisulphuret of lime is ex-
pedient.
Mercury and sulphur combine in the dry
way by trituration and by heat, forming a
black powder; but the species of compounds
PALLADIUM. 131
and quantities of the ingredients combining
in this mode, have not been ascertained.
17. Sulphur et of palladium. '{
Berzelius exposed 15 grains of palladium
filings mixed with as much sulphur to a heat
sufficient to expel the uncombined sulphur.
The increase of weight was 28 per cent, upon
the palladium ; when exposed afresh with sul-
phur to heat, no addition was made to the
weight.
Vauquelin heated 100 parts of the triple
salt of palladium with an equal weight of sul-
phur, and obtained 52 parts of a blueish white
sulphuret, very hard, and when broken ex-
hibiting brilliant plates in its fracture. He
had previously found that TOO salt contained
40 to 42 of metal : hence 100 metal combin-
ed with from 24 to 30 of sulphur. This
agrees nearly with the above results of Berze-r
lius. A very high degree of heat expels the
sulphur and oxidizes the metal ; but a more
moderate heat leaves the palladium of a silver
white colour and nearly pure. According to
this the atom of protosulphuret of palladium
must consist of 50 palladium, and 14 sul-
phur.
132 SULPHURETS.
18. Sulphur et of rhodium.
Vauquelin found that 4 parts of the ammo-
nia-muriate of rhodium (containing 28 or 29
percent, of metal) being* mixed with an equal
weight of sulphur, and heated, a blueish
white button was obtained, weighing 1.4.
Hence 100 metal seem to take 25 of sulphur ;
and allowing this to be the protosulphuret of
rhodium, the atom must consist of one rhodium
56, and one sulphur 14, making the whole
weight 70.
19. Sulphuret of iridium.
According to Vauquelin, 100 parts of the
ammonia-muriate of iridium heated with as
much sulphur, ^ield 60 parts of black powder
resembling^the other metallic sulphurets ; but
100 parts of the salt were found to yield from
42 to 45 of metal. Now supposing the last
number the most correct, it should seem that
3 parts iridium take 1 sulphur, or 100 take 33|.
This being supposed the protosulphuret, the
atom of iridium must be 42, and that of the
sulphuret 56.
20. Sulphuret of osmium.
It is as yet unknown whether any combi-
nation of sulphur and osmium exists.
COPPER. 133
21. Sulphur ets of copper.
Copper readily unites with sulphur both in
the dry and humid way. When 3 parts of
copper filings are mixed with 1 part of sul-
phur, and heat applied, a brilliant combus-
tion ensues, which indicates the union of the
two bodies. Copper leaf burns in the fumes
of sulphur, as fierzelius has observed, with
great brilliancy.
The protosalphuret of copper obtained by
these similar methods, when pulverized, is
black or dark coloured; it has been analyzed
by various authors, who nearly agree in their
results. Proust finds 100 copper unite with
28 sulphur; Wenzel, 100 copper and 25 sul-
phur; Vauquelin, 100 copper and 27 sulphur;
and Berzelius 100 copper and 25 sulphur.
If the atom of copper be 56, and that of
sulphur 14, the atom of protosulphuret of
copper will be 70; which gives just 100 cop-
per and 25 sulphur.
The protosulphuret may also be formed in
the humid way, by sending sulphuretted hy-
drogen gas or a hydrosulphuret into a solution
of protomuriate of copper, or amongst the
recently precipitated protoxide of copper.
Deutosulphuret of copper. This compound
is formed whenever sulphuretted hydrogen gas
134 SULPHURETS.
or a hydrosulphuret is sent into a solution of
salt containing the deutoxide, or into the
deutoxide just precipitated from any acid. It
is a dark brown powder not differing much in
appearance from the protosulphuret. It con-
sists of 100 copper and 50 sulphur; the
weight of the atom is 84.
Quadrisulphuret of copper. This compound
is formed by mixing quadrisulphuret of lime
with a salt of the deutoxide of copper, and
diluting the solution. A light brown precipi-
tate falls immediately, which is the quadri-
sulphuret of copper. It burns with* a blue
flame, and leaves the protosulphuret. The
atom consists of 56 copper and 56 sulphur,
or weighs 112; and hence the sulphuret con-
sists of equal parts copper and sulphur.
The blue hydrate of copper recently preci-
pitated from a salt of copper and washed, acts
upon quadrisulphuret of lime ; the results, ac-
cording to my experience, is quadrisulphuret
of copper, and the oxygen unites with the
sulphur remaining in the liquor.
22. Sulphurets of iron.
Sulphur may be united to iron either by the
dry or humid way, and that in various pro-
portions.
IRON. 135
Protosulphuret of iron. This compound may
be formed by passing a hydrosulphuret into a
solution of the green oxide in any acid. It
is a black powder. It may also be formed by
rubbing a highly heated bar of iron with a
roll of sulphur; the two unite in a fluid form
and soon congeal into a brownish black mass.
It is too a natural production, though not
very common; excellent analyses of it, as
well as of the common pyrites, were some time
ago given by Mr. Hatchett. (See Nicholson's
Journ. Vol. 10.) The protosulphuret is mag-
netic in a considerable degree; it is soluble in
acids, and yields sulphuretted hydrogen. It
is proper to notice that the sulphuret of iron
is not precipitated from solutions by sulphu-
retted hydrogen simply or without a base.
According to Mr. Hatchett this sulphuret
consists of 100 iron, and 57 sulphur, which
corresponds with 1 atom iron 25, and 1 of sul-
phur, 14, nearly.
Deutosulphuret of- iron. This is a natural
production frequently met with, and in vari-
ous forms; it is called pyrites, or iron pyrites;
it is a yellowish mineral and often appears
when broken, of a radiated texture, but
sometimes it is crystallized in cubes or do-
decaedrons. Acids have little effect upon it,
except the nitric, which when diluted attacks
136 SULPHURETS.
both the sulphur and iron ; much nitrous gas
is produced, the iron is dissolved, and the
sulphur chiefly converted into sulphuric acid.
This sulphuret consists, according to Proust,
of 100 iron, and 90 sulphur, and with this
Bucholz recently agrees (Nichols. 27 — 356) ;
but Hatchett makes it 100 iron, and 112 sul-
phur. From an experiment of my own on
the radiated pyrites, I found nearly equal parts
of iron and sulphur. One atom of iron (25,)
and two of sulphur (28,) would give 100 to 112;
but if the atom of sulphur be only 13, it gives
100 iron to 104 sulphur. Mr. Hatchett un-
fortunately calculating the proportions of the
ingredients in 100 sulphuret, instead of on
100 iron, did not notice that the sulphur in the
common pyrites is just double of that in the
magnetic pyrites.
Quinsulphuret of iron. This combination
consisting of 5 atoms of sulphur with 1 of iron,
is formed by mixing a solution of green sul-
phate of iron with quadrisulphuret of lime in
due proportion. I found 50 measures sulphate
1.168 saturate 310 of 1.05 sulphuret diluted
so as to become 6 oz. ; this yielded 14 grs. dried
sulphuret of iron — 3.6 iron, known to be in
the sulphate, and 10.4 sulphur ; the liquid con-
tained 2+ sulphur combined with the lime and
oxygen of the oxide; for it took 2.3 oxygen
IRON. 137
by means of oxymuriate of lime to convert
the sulphur into sulphuric acid together with
1 + from the oxide, making 3 + oxygen,
which unites to 2+ sulphur to constitute 5+
sulphuricacid; and this quantity of acid was
found to exist by muriate of barytes together
with five more brought in by the sulphate of
iron. This sulphuret is a yellowish brown
powder ; it readily exhales sulphur by heat and
is reduced to the protosulphuret; but in the
open air it burns with a blue flame and leaves
the protosulphuret partially, as I apprehend,
oxidized. The theory of the formation of
quinsulphuret seems to be this: 3 atoms of
quadrisulphuret of lime are requisite to satu-
rate 2 of sulphate of iron ; the 2 atoms of sul-
phuric acid seize 2 of lime, three fourths of
the sulphur unite to the iron, and one fourth
to its oxygen, forming 2 atoms of oxide of
sulphur, which attack the 3d atom of sul-
phuret and decompose it, giving its sulphur
to the iron, and neutralizing the lime (for
the liquid is found neutral). In this way 10
atoms of sulphur are united to 2 of iron,
and 2 of sulphur to 2 of oxygen, with one of
lime, which last compound remains in solution,
and the oxide of sulphur may be conver-
ted into sulphuric acid immediately by the
application of oxymuriate of lime.
VOL. II. S
138 SULPHURETS.
It is remarkable that neither the green nor
the yellow oxides of iron, even when recently
precipitated and not dried, seems capable of
decomposing quadrisulphuret of lime.
It is probable that trisulphuret and quadri-
sulphuret of iron may be formed ; but I have
not ascertained the truth of this opinion.
23. Sulphur els of nickel.
Prolosuiphuret. According to Proust, nickel
unites to sulphur by heat, so that 100 take 46
or 48; the sulphuret is of the colour of com-
mon pyrites. (Journ.de Physique, 63 and
■80). According to Mr. Ed. Davy 100 nickel
take ,54. sulphur. By saturating a solution of
nitrate of nickel with hydrosulphuret of lime
I obtained 40 grains from 33 protoxide or 26
metal. This was evidently the protosulphu-
ret ; it was a fine black powder, and consists
pf 100 metal and 54 sulphur.
Quinsulphuret. This compound may be ob-
tained from nitrate of nickel and quadrisul-
phuret of lime, in the same manner as that of
iron. It is a deep black powder, and consists
of 100 nickel, and 215 sulphur. By expo-
sure to heat, the greatest part of the sulphur
burns off, and the rest may be expelled by an
increase of temperature.
Probably intermediate sulphu rets - may be
TIN. 139
formed; but I have not pursued the investi-
gation.
24. Sulphur ets of tin.
Sulphur and tin unite both in the dry and
humid way, and in various proportions.
Protosulphuret. This may be readily form-
ed in the dry way as follows; let 100
grains of tin be fused in a small iron
ladle and heated to 6 or 8 hundred degrees
Fahrenheit; let then small pieces of sulphur
of 10 or 20 grains be successively dropped
into the fused metal : a copious blue flame
will instantly arise each time, and a glowing
heat will take place, when the sulphur and tin
are in contact; as soon as this ceases, another
fragment of sulphur must be dropped in, and
this two or three times repeated, heating it at
last to a perfect red; the mass may then be
taken out and pounded in a mortar ; a great
part of it will be a pulverulent powdery but
some portions of malleable metal will still be
mixed with it, which may be separated by a
sieve. This must be again heated and treated
with sulphur as before, and the whole mass
will be converted to a sulphuret. I find that
100 parts of tin become in this way 127 grains ;
which is the due proportion of 52 tin and 14
sulphur, so that no loss of tin is sustained by
140 SULPHUKETS.
the process when duly managed. According
to Wenzel, 100 tin take 18 sulphur ; Berg-
man, 25; Pelletier, 15 to 20; Proust, 20;
but Dr. John Davy and Berzelius find nearly
27 as above stated, and I have no doubt it is
near the truth.
The protosulphuret of tin is a dark grey
shining powder, with a streak like molybde-
na or plumbago; it is not ;much different in
colour and appearance from native sulphuret
of antimony, only less blue. It is soluble in
muriatic acid by heat, and yields sulphuretted
hydrogen and protomuriate of tin.
Deutosulphuret. This compound is better
known than the former : it may be formed in
various ways; one is by heating a mixture of
deutoxide of tin and sulphur in a retort almost
to a red heat ; sulphur sublimes and sulphur-
ous acid is disengaged, and there remains a
yellow, light shining, flaky mass at the bottom
of the retort which is the sulphuret. It was
formerly called aurum musivum or mosaic gold.
Pelletier and Proust were of opinion that this
product is a sulphuretted oxide of tin; but
Dr. John Davy and Berzelius have rendered
it more probable that it is a true deutosulphu-
ret, consisting of 100 tin and 54 sulphur. It is
insoluble in muriatic or nitric acid, but slowly
soluble by the compound of the two acids; it
TIN. 141
is also soluble in potash by heat. By expos-
ing it to a bright red heat, it burns with a blue
flame and leaves a yellowish powder which
does not seem to differ much from proto-
sulphuret.
Berzelius distilled a mixture of protosul-
phuret and sulphur at a low red heat, and ob-
tained a mass of a yellow grey colour and
metallic lustre, which consisted of 100 tin,
and 14 sulphur, which is just the mean sul-
phur between the other two. This would
seem to indicate that a compound of the two
sulphurets, 1 atom to 1, is capable of being
formed.
Hydrosulphuret of tin minor. This com-
pound is formed according to Proust, when
sulphuretted hydrogen, or an alkaline or ear-
thy hydrosulphuret is passed into a solution of
protomuriate of tin. It is of a brown or
dark coffee colour when precipitated, and
black when dried. By heat it yields water and
protosulphuret. From some experiments I am
inclined to believe, that it is formed of 1 atom
protosulphuret and 1 of water: or, which is
the same, 1 atom protoxide of tin and 1 of
sulphuretted hydrogen, If this be right it
may be said to be a compound of 100 tin, 27
sulphur and 15 water.
Hydrosulphuret of tin major. This name is
142 SULFHURETS.
given by Proust to the yellow compound
thrown down by sulphuretted hydrogen or by
hydrosulphurets from solutions of the deutox-
ide of tin. When dried moderately, the
precipitate is of a dull yellow colour, and vi-
treous fracture, but I find it is almost black,
dried in a heat of 150° or upwards. By mo-
derate heat it yields water, sulphurous acid,
sulphur, and the residue is deutosulphuret of
tin according to Proust. I heated 4 parts of
the above previously dried so as to become a
black vitreous powder ; it burned feebly with
a blue flame, and after being made mode-
rately red, left nearly 3 parts exactly resem-
bling the artificial protosulphuret. I believe
the dried precipitate will be found to be con-
stituted of 1 atom tin, 2 sulphur and 1 water;
that is, 100 tin, 54 sulphur and 15 water
= 169 by weight ; and that it loses 27 sulphur
and 15 water by a red heat, which reduces the
weight just one-fourth.
Quinsulphuret of tin. This is obtained in
the humid way, by first precipitating the ox-
ide, and then putting quadrisulphuret of lime
or potash to the liquid containing the precipi-
tate, till the liquid after agitation and subsi-
dence of the precipitate continues of a yel-
lowish colour. I found that 31 measures of
protomuriate of tin of 1.377 = 7 grains acid,
TIN. 143
7.5 tin and 1 oxygen, precipitated by 10 oz.
lime water, required 450 measures of 1.40
sulphuret of lime, containing* 16 sulphur and
7.2 lime, for their saturation. The residuary
liquid was nearly colourless, and the precipi-
tate dried in an oven of 100* or more, for 10
hours, weighed 17 grains besides loss in the ope-
ration. It was a yellow, vitreous mass, and
when pulverized and heated, burned with a
blue flame, and lost 40 per cent, in weight;
the residue was a yellow grey colour, and
seemed to be like the intermediate sulphuret
of Berzelius ; it would not give sulphuretted
hydrogen by hot muriatic acid. Now if 52
(1 atom tin) : 70 (5 atoms sulphur) ; : 7.5
tin : 10 + sulphur; hence the sulphuret should
have weighed 17.5 grains, which was the
observed weight, allowing § grain for loss.
According to this, 100 tin combine with 135
sulphur, and when burnt, the 235 are redu-
ced to 140, the weight observed by Berzelius
in the instance alluded to. The liquid requir-
ed 5 grains of oxygen from oxy muriate of
lime, to convert the sulphur into sulphuric
acid, and the weight of this acid, found by
muriate of barytes, was 11 grains, indicating
4.4 sulphur. It may be observed that the 4.4
grains, and 10 grains, do not make up the
whole (16) of the sulphuret of lime; but the
144 SULPHURETS.
reason I apprehend was, that the quadrisul-
phuret was old, and did not contain the full
share of sulphur, it being- usual for a small
part to fall by-time.
The deutomuriate of tin, precipitating1 the
oxide in like manner, yielded a sulphuret ra-
ther lighter yellow than the above; about 10
tin gave 25 grains of sulphuret dried in a
temperature of 80 to 100°. This compound
still contained water, and 1 suspect it will be
found constituted of 1 atom tin, 5 sulphur,
and 2 water.
25. Sulphurets of lead.
Lead combines with sulphur in various pro-
portions, some of which are natural produc-
tions of great purity.
Protosulphuret. This is a natural produc-
tion which is called galena; it is of lead grey
colour and metallic appearance, and is found
both in masses and crystallized; its sp. gr. is
about 7.5. It may be formed artificially by
heating lead or its oxide with sulphur; also by
treating a solution of lead with sulphuretted
hydrogen or with a hydrosulphuret. Authors
are well agreed as to the proportions of the
ingredients; 100 lead combine with from 15
to 16 sulphur. That is, 90 lead with 14 sul-
phur; orl atom of lead withl of sulphur.
LEAD. 145
Deutosulphuret. Dr. Thomson mentions a
natural production or species of galena which
contains twice the quantity of sulphur of that
above. I have reason to believe that this
compound is easily formed in the humid way,
by treating the precipitated oxide with the
due quantity of quadrisulphuret of lime.
Trisulphuret and quadrisulphuret. These
compounds, I find, may be formed by means of
quadrisulphuret of lime or potash. When a
solution of any salt of lead or the recently
precipitated and moist oxide, is treated with
the requisite quantity of quadrisulphuret of
lime, a combination consisting of 1 atom of
lead and 3 of sulphur is formed. It is a black
powder not differing much in appearance2 from
the protosulphuret; it is lighter and more
spongy. It consists of 100 lead and 46 or
47 sulphur. The due proportions of the ele-
ments to form the above compound are, lead
100 parts in solution, and sulphur, 62 parts; \
of the sulphur is retained by the lime, and
may be converted into sulphuric acid instantly
by the addition of as much oxymuriate of
lime as contains oxygen equal in weight to
the sulphur, as it has already as much oxygen
as converts it into sulphurous oxide, derived
from the oxide of lead.
Quadrisulphuret of lead is to be obtained la
VOL. II. T
146 SULPHURETS.
the same way ; only we must have an excess
of the sulphuret of lime, or more than 80 sul-
phur for 100 lead in solution, as ^ part of the
sulphur at least is retained by the lime. The
quadrisulphuret is a black powder like the
others; it burns with a blue flame and loses
nearly 40 per cent., the residue being" still
black. It consists of 100 lead and 62 sul-
phur.
I have not ascertained whether any higher
sulphuret of lead is capable of being formed
this way.
It has been already noticed (page 109),
that a beautiful white, silvery sulphuretted
sulphite of lead is formed and gradually pre-
cipitated, when nitrate of lead is dropped into
a solution where as much black quadrisulphu-
ret of lead has been just thrown down as the
sulphuret of lime can form.
26. Sulplmrets of zinc.
•
Zinc and sulphur are scarcely to be united
directly by heat ; but by heating the oxide of
zinc and sulphur together, a combination is
effected; part of the sulphur carries off the
oxygen in sulphurous acid, and part combines
with the zinc. Mineralogists give the name
zinc. 147
of blende to a mineral which is chiefly the
protosulphuret of zinc : its colour is yellow-
ish, brown, or black almost like galena: its
specific gravity is usually 3.9 or 4.
Protosulphuret. The above artificial com-
pound, or the mineral, may be taken as ex-
amples of the union of 1 atom zinc and 1
sulphur. But the most correct and conveni-
ent way of forming it for the purpose of che-
mical investiagtion is, to drop a given portion
of some salt of zinc into a dilute hydrosul-
phuret. A white precipitate falls, which
when dried becomes a dark cream colour. It
is found to consist of 2 parts zinc and 1 of
sulphur nearly; that is, of 29 parts zinc and
14 sulphur.
Deutosulphuret, trisulphuret, &c. of zinc.
These combinations may be made, up to the
5th or quinsulphuret, in the humid way by qua-
drisulphuret of lime, &c. The oxide may be
first precipitated by lime water, or not, as we
please, and then treated with quadrisulphu-
ret according to the degree of sulphuration
required. I found 100 measures of 1.29 ni-
trate of zinc with 2500 of 1.026 sulphuret of
lime yield 40 grs. dry sulphuret zinc, of a
yellowish white colour; the liquid was found
to retain 13 or 14 grains of sulphur, by con-
verting it into sulphuric acid by means of
148 SULPHURETS.
oxymuriate of lime. The nitrate contained
llf zinc and 2.8 oxygen; so that about 28
sulphur had combined with the zinc, and
about 14 remained in solution, or 4. of the
whole, as has been already explained. By
proportion, if 11 f : 28 : : 29 : 70; or 1 atom
of zinc (29) combines with 5 atoms of sul-
phur (70). The intermediate combinations
I have not particularly examined ; they do
not differ much in appearance from the one
just described; they burn blue and are redu-
ced by it to the protosulphuret ; and they
give sulphuretted hydrogen by muriatic acid.
27 and 28. Sulphur ets of potassium
and sodium.
•According to Davy and Gay Lussac, po-
tassium and sodium unite with sulphur by
heat with vivid combustion. The compounds
appear to be protosulphurets, that of potash
being nearly as 35 potassium to 14 sulphur,
and that of sodium as 21 sodium to 14 sul-
phur. When potassium and sodium are heat-
ed along with sulphuretted hydrogen, an uni-
on likewise takes place; two atoms of gas
unite to one of the metals, except that 1 atom
of hydrogen is liberated, corresponding of
course in quantity to that liberated by treating
BISMUTH. 149
them with water. When the compound thus
formed is treated with muriatic or sulphuric
acid, the same quantity of sulphuretted hy-
drogen nearly is liberated that was originally
combined. So that the compound may be
regarded as sulphuretted hydrogen united to
the protosulphurets. The colour of these sul-
phurets varies from grey to yellowor reddish.
29. Sulphurets of bismuth.
Protosulphuret. Bismuth combines with sul-
phur by heat, in the manner already described
in the account of tin sulphurets. I found 100
parts bismuth in this way combine with 22
sulphur after 4 operations : this is therefore the
protosulphuret or 1 atom bismuth (62) with
1 of sulphur (14). It may also be formed by
substituting the oxide of bismuth for the me-
tal. It has a dark brown or black metallic
appearance, much like that of tin. It yields
sulphuretted hydrogen in heated muriatic
acid.
Hydrosulphuret of bismuth. When a solu-
tion of bismuth in nitro-muriatic acid i»
dropped into hydrosulphuret of lime, a black
powder precipitates, which, when dried in the
common temperature, appears to be hydro-
sulphuret of bismuth, or one atom sulphu-
150 SULPHURETS.
retted hydrogen and one oxide of bismuth. It
yields sulphuretted hydrogen by cold muriatic
acid. But if the precipitate be dried in a
heat of about 200°, the atom of water seems
to be expelled, and there remains only the
protosulphuret. Thus I found 69 parts ox-
ide of bismuth unite to 15 sulphuretted hy-
drogen to form 84 hydrosulphuret of bismuth,
when dried in the air; but upon being heated
a little, it lost 8 parts of water and was redu-
ced to the protosulphuret, retaining in great
part the same appearance as before.
Deutosulphuret and trisulphuret of bismuth
with oxygen. When nitro-muriate of bismuth
is thrown into water the oxide is precipitated ;
if the acid water be decanted, quadrisulphu-
ret of lime be put to the moist oxide and due
agitation be used, the oxide abstracts sul-
phur from the lime so as to obtain 2 or 3
atoms for each one, if the sulphur be suffici-
ent in quantity. To 6 oz. water I put 100
grain measures of 1.286 nitro-muriate, which
I knew from its formation contained 20 ox-
ide; after the precipitate had subsided I
poured off 5 oz. of acid water, and to the re-
maining precipitate diluted with water I put
300 of 1 .056 sulphuret of lime and agitated
for 10 minutes. There were obtained 33
grains of brownish black sulphuret of bis-
ANTIMONY. 151
niuth dried for some hours in a temperature of
120°. I put the above 33 grains into a gas bot-
tle with 100 muriatic acid and boiled it ; there
were obtained only 2 or 3 cubic inches of sul-
phuretted hydrogen, the oxide was dissolved
and sulphur liberated; the sulphur collected
and dried weighed 9 grains, and the oxide
precipitated again from the muriatic acid by
water and dried, weighed 17 grains, besides
loss. From this it is evident the oxygen of
the oxide must have been chiefly retained in
the compound, and must have united to 2,
and in great part to 3, atoms of sulphur. For
20 oxide would require 12 sulphur to form
trisulphuretted oxide; and there was evidence
of its having nearly, if not wholly, that
quantity.
30. Siilphurets of antimony.
Protosulphuret. This is a natural produc-
tion, and found in the state of a dark grey
mineral of metallic appearance, and of the
sp. gr. 4.2. It may also be formed artificially
by uniting metallic antimony and sulphur by
heat. Most authors nearly concur in assign-
ing to it 74 parts antimony and %Q sulphur,
per cent. That is, 1 atom antimony (40) and
and 1 of sulphur (14). It yields sulphuretted
152 SULPHTXRETS.
hydrogen by muriatic acid and heat, and a
solution of the metallic oxide is obtained.
Hydrosulplmret. When antimony is preci-
pitated from a solution, by sulphuretted hy-
drogen or a hydrosulphuret, or from an alka-
line solution of the sulphuret by an acid, it ap-
pears in the form of an orange yellow pow-
der, denominated golden sulphuret. It is
constituted of 1 atom sulphuretted hydrogen
and 1 of protoxide of antimony; it readily
yields sulphuretted hydrogen by muriatic acid,
and the oxide combines with this acid. Ex-
posed to heat, water is expelled and protosul-
phuret left. It is constituted of 40 antimony,
7 oxygen, 14 sulphur and 1 hydrogen; or of
54 protosulphuret and 8 water.
Bisulphuretted, trisulphuretted and quadri-
sulphuretted oxide of antimony. When crystal-
lized muriate of antimony is agitated along
with dilute quadrisulphuret of lime, an orange
yellow compound- is formed, consisting of the
oxide and sulphur. To 350 quadrisulphuret of
lime> diluted with lime water, I put 22 grains
moist crystals of muriate, and agitated well
for some time. Got 26 grains dry yellow sul-
phuret, which heated burned blue, and left
from 13 to 14 black grey sulphuret, equal to
10 antimony nearly ; hence it must have been
a quadrisulphuret, or rather sulphuretted ox-
TELLURIUM. 153
ide ; for, by heating this compound in muri-
atic acid, a solution is obtained and sulphur
liberated without the extrication of gas. Less
of the sulphuret of lime would have produ-
ced a sulphuret of the same colour, but con-
taining less of sulphur; so that it is evi-
dent various proportions may exist in combi-
nation. Instead of the crystallized muriate,
the recently precipitated oxide, nearly free
from acid, may be used to produce these
compounds.
31. Sulphuret of tellurium.
Tellurium unites with nearly its weight of
sulphur, by heat, according to Davy. It is
probable that as usual in such cases, a proto-
sulphuret is formed. This would lead to the
conclusion that the atom of tellurium is only
equal in weight to that of sulphur; which
does not accord with results from the other
combinations of tellurium, and hence the
above fact may riot perhaps be sufficiently
ascertained.
32. Sulphurets of arsenic.
Arsenic may be combined with sulphur by
exposing a mixture of the metal and sulphur
or of the white oxide and sulphur, to a heat
VOL. II. U
154 SULPHURETS.
approaching to redness. In the latter case
more sulphur is required, because the oxygen
is carried off in the shape of sulphurous acid.
Three parts of arsenic with two, three or
more of sulphur may be used; the heat should
be less if a greater proportion of sulphur is in-
tended to be united. As both the elements
are volatile in a moderate heat, and that in
unequal degrees, considerable difficulty occurs
in ascertaining by the synthetic mode, the
proportions of the elements combined; if
too little heat be used, only a mechanical
mixture is obtained, of any proportions we
please; if too much heat be used, part of the
arsenic as well as part of the sulphur sublimes,
and the sulphuret itself sublimes at a heat not
much exceeding that required for their union.
Hence, in a great measure we have the dis-
cordant results of those who have taken the
synthetic method. The analytic method is
to be preferred, and those who have taken it
have succeeded the best; but even this is at-
tended with greater difficulties than with
most of the other sulphurets.
The artificial sulphurets of arsenic consti-
tute two varieties chiefly, and these are also
found native in various parts of the earth.
1; Protosulphuret* Native sulphuret: of ar-
senic* called orpiment, is found in Turkey
ARSENIC. 155
and elsewhere in considerable masses; when
broken it exhibits a foliated structure, some-
what flexible, and of a brilliant golden yel-
low colour. Its specific gravity is usually
about 3.2; at least that was the case with, the
specimen I used. When heated so as to be
near melting, its surface reddens, probably
by the loss of sulphur. The same sulphuret
is procured artificially in the humid way
whenever a solution of the oxide of arsenic
in water, &c. is treated with sulphuretted hy-
drogen, or a hydrosulphuret, and afterwards
with an acid; or when this or any other spe-
cies of sulphuret of arsenic is dissolved in an
alkali and the solution treated with an acid.
Kir wan in 1796 states, that it is generally
thought to consist of 100 arsenic and 11 sul-
phur, but that Westrumb says it contains 100
arsenic and 400 sulphur, which Kirwan thinks
more probable; they are both however very
wide of the truth. Thenard, in the 59 Vol.
of the An. de Chimie, 1806, asserts that it
consists of 100 arsenic and 15 sulphur; but
he does not point out the experiments on which
this result rests; and it is not very near the
truth. Laugier in the same An. Vol. 85, for
1813, in a paper of great merit, finds the native
orpiment to contain 38 per cent, of sulphur;
his method is to dissolve the orpiment in warm
156 SULPHURETS.
dilute nitric acid ; to precipitate the sulphu-
ric acid by nitrate of barytes, and from the
sulphate of barytes infer the sulphur ; the rest
he considers as arsenic, not knowing how to
detach the arsenic acid from the nitric acid so
as to determine the arsenic by experiment. I
have pursued this method with the advantage
of being able to determine the arsenic as well
as the sulphur: Ten grains of orpiment in
fine powder were dissolved in 100 measures
of 1.346 nitric acid diluted with as much wa-
ter, by digesting in a heat so as to keep a
constant moderate effervescence for about 2
hours. The liquid obtained, being diluted
yielded 536 measures of 1.061. By carefully
and gradually dropping in muriate of barytes
I found 150 measures of 1.162 just sufficient
to saturate the sulphuric acid, and the sul-
phate of barytes produced dry was 28 grains^
the loss I estimated 1 grain : now one third
part being sulphuric acid, and f. of the acid
being sulphur, we have 44 of 29 = 3.87, or
3.9 for sulphur. The residuary liquid was
then treated with lime water till an excess
was manifest) and produced no farther pre-r
cipitate; the arseniate of lime was collected
and dried) and gave 16 grains. Now I had
determined by experiments hereafter to be re-
lated, that 4 of arseniate of lime are acid
ARSENIC. 157
and $ of the acid are arsenic; hence ; ^8T of
16= 6.1 for the arsenic, which added to 3.9
sulphur, make up the 10 grains of orpiment.
When this orpiment is treated with caus-
tic alkali, it is completely dissolved; it is
thrown down by acids I find unaltered. If
61 arsenic combine with 39 sulphur, 100
must take 64 nearly; which corresponds with
1 atom of each, or 21 arsenic + 13 or 14 sul-
phur. ' *
Subprotosulphuret. Sulphur and arsenic are
found native in certain places, combined in
masses of a brownish red or orange colour
and glassy fracture : this combination is called
realgar, and is also manufactured in large
quantities in Saxony, chiefly for the use of
calico-printers. Its constitution and specific
gravity vary considerably, owing chiefly I
imagine to the greater or less heat to which
it is exposed, and to the proportions of the
elements in the first mixture. I have speci-
mens of 3.3 and 3.7 sp. gr. ; and it is probable
these are not the extremes; the heaviest is
the darkest colour. Of course the heaviest
contains the most arsenic, and I have reason
to believe that the sp. gr. is nearly as good a
test of the proportions of the elements as
chemical analysis. Realgar when pulverized
is of an orange colour: it is much sooner dis-
158 SULPHURETS.
solved in dilute nitric acid and requires less,
than the same weight of orpiment. Caustic
alkali dissolves it partially, taking up the
protosulphuret and leaving the excess of
arsenic, the quantity of which may hence be
ascertained. Ten grains of realgar took 80
measures of 1.347 nitric acid, diluted with
as much water ; digested in a heat of about
150° it was all dissolved in If hour, and
yielded 536 liquid of 1.05 sp. gravity. This
treated as before gave 24 sulphate of barytes
= 3.2 sulphur, and 18 arseniate of lime = 6.9
arsenic. This result agrees nearly with JLau-
gier's in regard to the sulphur in native real-
gar: but the artificial realgar, which he
made by combining arsenic and sulphur,
yielded him 40 per cent, sulphur by my esti-
mation and 42 by his own : the sp. gravity
of his artificial realgar is not given. Wes-
trumb estimates realgar at 100 arsenic and
25 sulphur, and Thenard at 100 arsenic and
33 sulphur. But from the above it must be
concluded to contain 100 arsenic and 45 to 50
of sulphur. One hundred parts of the same
realgar heated in caustic potash were resolved
into 78 orpiment taken up by the liquid and
22 arsenic precipitated.
It appears to me most probable that a true
subsulphuret would be most convenient for
ARSENIC. 159
the printers' use, or one containing 100 ar-
senic and 32 sulphur, that is, 2 atoms arsenic
and 1 sulphur. The object being1 to deoxi-
dize indigo and obtain it in solution in a
green state, we may suppose that 1 atom
arsenic takes the oxygen from the indigo and
then forms arseniate of lime which precipi-
tates, whilst the other atom in union with
the sulphur, takes the green indigo and unites
it to the potash, making a quadruple com-
pound of arsenic, sulphur, green indigo and
potash in solution. If this view be right the
heaviest and darkest coloured realgar of com-
merce must be the most advantageous for this
purpose. Some printers however prefer the
protosulphuret.
Deutosulphuret. Proust, by heating 100
arsenic with 300 sulphur in one instance got
222 parts, and in another 234 parts of a
transparent deep greenish yellow sulphiiret,
(Jour, de Phys. 59— p. 406. 1804). Now it
is very remarkable that if we take the atom
of sulphur at 13 and that of arsenic 21, one
of this and two of the former will be found
as 100 to 124, together 224; but if sulphur
be 14, then the proportion will be 100 to 133,
together 233. It seems more than probable
that Proust had accidentally used that degree
of heat in the combination which is requisite
160 SULPHTJRETS.
for forming the deutosulphuret. It is proba-
ble too that Laugier always used a higher
heat, as he uniformly obtained the same
(lower) sulphuret whatever were the propor-
tions, the excess of either being sublimed or
separated by the heat.
Trisulphuret, quadrisulphuret, &c. When
a solution of the oxide of arsenic is treated
with quadrisulphuret of lime, little precipi-
tate appears; but if muriatic acid be dropped
in, a fine yellow precipitate is formed. This
I have reason to think is sometimes a trisul-
phuret, and at other times a quadrisulphuret
or higher; but it is difficult to investigate
these compounds, and on that account I speak
with some uncertainty.
33. Sulphuret of cobalt.
Sulphuretted hydrogen does not precipitate
cobalt from solutions containing that metal ;
but hydrosulphurets precipitate it.
Protosulphuret. This compound is obtained
whenever a neutral solution of cobalt is treat-
ed with hydrosulphuret of lime, &c. or it may
be obtained from any acid solution by first
precipitating the blue oxide by an alkali, and
then introducing sulphuretted hydrogen into
the mixture- By this last method I found a
COBALT. 161
solution previously known to contain 44 parts
by weight of protoxide to absorb 15 parts of
sulphuretted hydrogen; when filtered and
dried in a heat of 100° it yielded 51 parts of
protosulphuret. In appearance it resembles
many of the other black sulphurets. It con-
sists of 100 cobalt and 38 sulphur; Proust
finds 40 sulphur, but he considers it only an
approximation.
The same sulphuret may be formed by
heating the oxides of cobalt and sulphur toge-
ther to a red heat; at least a combination is
effected as Proust observed, but I have not in-
vestigated the proportions. Sulphur does not
seem to combine with the metal in this way.
Deutosulphuret. . . . dodecasulphuret. When
the recently precipitated and moist oxide of
cobalt, the neutral muriate, or acid muriate
of cobalt, as well as other salts of the same,
are treated with dilute quadrisulphuret of
lime, sulphurets of cobalt are formed in va-
rious proportions according to the ingredients,
from the deutosulphuret to the dodecasulphu-
ret: these precipitates are all black and not
easily distinguished in appearance ; but there
is reason to believe they are true chemical
compounds.
VOL. II. X
102 SfJLPHURETS.
34. Sulphurets of manganese.
Though sulphur and manganese do not
unite directly, they can be brought into union
by intermediate bodies, both in the dry and
humid way.
Protosutyihuret. This compound may be
formed by heating to a low red, a mixture of
the oxide of manganese and sulphur, or of
the white carbonate of manganese and sul-
phur; or it may be formed by treating a so-
lution of manganese by a hydrosulphuret,
(sulphuretted hydrogen not producing any
precipitate) ; this last method seems to pro-
duce a dry hydrosulphuret of manganese,
which being heated to red nearly, parts with
water and a little sulphur and there remains
the protosulphuret. The protosulphuret is of
a snuff brown colour; but the hydrosulphuret^
when recently precipitated is of a light drab
colour, which grows deeper when exposed to
the air, and when dried becomes brown like
the protosulphuret ; when heated, the colour
is not much changed. The hydrosulphuret
of manganese gives sulphuretted hydrogen by
cold muriatic acid, and the protosulphuret
gives the same by the acid heated.
The proportion of the elements in the pro-
CHROMIUM. 163
tosulphuret may be inferred from the fact that
the black oxide yields its own weight of pro-
tosulphuret; that is, 156 grains, composed of
100 metal and 56 oxygen give 156 of sulphu-
ret; hence the atom of metal, 25, unites with
one of sulphur, 14. I found 32 of the prot-
oxide in solution unite to 15 of sulphuretted
hydrogen to form 47 hydrosulphuret dried in
100Q. This lost about 8 parts or rather up-
wards by heat.
Deutosulphuret, trisulphuret and quadri-
salphuret. These may be formed by treating
neutral solutions of manganese, or the re-
cently precipitated oxide, by quadrisulphuret
of lime. They are formed somewhat slowly
and by considerable agitation with a smaller
or greater proportion of the lime sulphuret.
They are all light drab, and are reduced to
the protosulphuret by heat.
35. Sulphuret of chromium.
I have not had an opportunity of ascertain-
ing whether chromium or its oxides combine
with sulphur or not, though several attempts
were made for that purpose.
164 SULPHURETS.
36. Sulphuret of uranium
From the experiments of Bucholz it would
seem that uranium may be combined with
sulphur, but the proportions have not been
ascertained. (An. de Chimie. 56 — 142.)
37. Sulphuret of molybdenum.
From Bucholz and Klaproth's analyses of
molybdena it would seem that the native sul-
phuret consists of 60 metal and 40 sulphur;
but it does not appear whether this should be
considered as the protosulphuret or the deuto-
sulphuret. If it is the protosulphuret the
atom of molybdenum weighs 21, but if the
deutosulphuret, the atom of metal weighs 42 ;
and the atom of the sulphuret or molybdena
must weigh either 35 or 70.
38. Sulphuret of tungsten.
According to Berzelius, a sulphuret of
tungsten may be obtained, by heating a mix-
ture of tungstic acid and sulphuret of mer-
cury in the proportion of 1 to 4, in a cru-
cible. The mixture in his experiment was
covered with charcoal and the crucible inclos-
TITANIUM, &C. 165
ed in another containing charcoal; the whole
was then exposed to the heat of a furnace for
half an hour. The sulphuret obtained was a
greyish black powder; it was found to con-
sist of 100 metal and 33| sulphur, or about
3 metal to 1 sulphur. Hence this must be
the deutosulphnret if we consider the atom of
tungsten to be 84; but considering the high
degree of heat to which it was exposed, it
would seem more likely to be the protosul-
phuret ; if so, the atom of tungsten must be
considered as 42 only, or half of the other
number.
39. Sulphuret of titanium.
No compound of titanium and sulphur has
been formed.
40. Sulphuret of columbium.
This combination is unknown.
41. Sulphuret of cerium.
This combination is also unknown.
( 166 )
SECTION 15.
EARTHY, ALKALINE, METALLIC
AND OTHER PHOSPHURETS.
Phosphorus like sulphur is capable of be-
ing" combined with several of the earths and
metals as well as with other bodies; but the
combination is not so easily effected, and the
products are less interesting" than those of sul-
phur : from considerations of these circum-
stances together with those of the expence
and danger in making experiments on phos-
phorus we may account for, this class of bo-
dies being as yet imperfectly known.
Margraf in 1740 attempted to combine
phosphorus with many of the metals; but
his experiments were mostly unsuccessful.
Gensrembre in 1783 endeavoured to unite
phosphorus with the alkalies; in this he fail-
ed of success, but discovered the phosphuret
of hydrogen, or the spontaneously inflamma-
ble gas now denominated phosphuretted hy-
drogen. (Journal de Physique, 1785.)
In 1786 Mr. Kir wan published some expe-
riments on phosphuretted hydrogen, (Philos.
PHOSPHURETS. 167
Trans.); he ascertained that water impreg-
nated with this gas had the property of pre-
cipitating various metals from their solu-
tions.
The ingenious and indefatigable Pelletier
has more merit than any other person in his
investigations of the phosphurets. An im-
portant memoir of his on the manufacture of
phosphorus in the large, is given in the
Journal de Physique for 1785; in this he
states that 4 or 5 lbs. sulphuric acid are com-
monly requisite for 6 lbs. calcined bones; and
that from 18 lbs. calcined bones he obtained
by the usual process, 12 oz. of phosphorus*
In 1788 he read an essay on the phosphurets
of gold, platina, silver, copper, iron, lead and
tin. (An. de Chimie, 1—106). In 1790 he
published an essay on the combinations of
phosphorus with sulphur. {Ibid. 4—1). An
additional memoir was published in 1792 on
the same metallic phosphurets; and another
on the phosphurets of mercury, zinc, bismuth,
antimony, cobalt, nickel, manganese, arsenic
and the other metals.
M. Raymond in the Aii. de Chimie, 1791,
recommends, instead of potash, moist hydrate
of lime and phosphorus in order to obtain
phosphuretted hydrogen with greater facility;
and in the same Annals for 1800 he asserts*
168 PHOSPHURETS.
that water absorbs a considerable portion of
phosphuretted hydrogen, and becomes capa-
ble of precipitating metals from their solu-
tions in acids, and of forming phosphurets,
in this respect resembling sulphuretted hy-
drogen.
Mr. Tennant discovered in 1791 that car-
bonic acid combined with theearths and alka-
lies is capable of decomposition by phospho-
rus, in a red heat; and Dr. Pearson, follow-
ing up the discovery, found that pure or caus-
tic lime may be united to phosphorus by heat
so as to form phosphuret of lime; and that
this dry compound when put into water is de-
composed and gives out bubbles of phosphu-
retted hydrogen gas, which as usual explode
spontaneously on reaching the surface of the
water and coming into contact with the air.
In 1810 I published the method of analys-
ing phosphuretted hydrogen by Volta's eudi-
ometer ; having found that this gas and oxy-
gen may be mixed together in a narrow tube
without explosion and afterwards exploded as
other similar mixtures by an electric spark.
Dr. Thomson published an essay on phos-
phuretted hydrogen in the Annals of Philo-
sophy for August, 1816. He agrees with me
very nearly as to the constitution and proper-
ties of this gas, as far as I have gone \ but
HYDROGEN.
he has ascertained several additional proper-
ties of the gas, which I shall advert to in the
sequel.
Sir H. Davy and Gay Lussac have investi-
gated several compounds of phosphorus, par-
ticularly with muriatic and oxymuriatic acids,
and with the new metals potassium and so-
dium, which I shall have to notice in their
proper places.
Other authors have written on phosphurets
besides those I have mentioned, but they do
not require to be particularly distinguished in
this enumeration. We shall therefore pro-
ceed to describe the phosphurets more par-
ticularly.
1. Phosphuret of hydrogen.
Prom recent experiments which I have
made on phosphuretted hydrogen gas, I find
the account already given (Vol,. 1. page 456)
is deficient, and in several respects inaccurate ;
I shall therefore substitute the following, as
more perfect and correct.
Phosphuretted hydrogen may be obtained
nearly pure, by the methods recommended
by Dr. Thomson. Phosphuret of lime that
has been carefully secluded from the atmo-
sphere, may be put into a small phial filled
VO]L. n, Y
170 PHOSPHUKETS.
with water, acidulated by muriatic acid ; into
this a cork with a bent tube must be immedi-
ately put under water, so that the phial and
tube are both full of water; gas soon begins
to appear, which rising to the top of the phial,
expels a corresponding portion of water, and
in due time the gas itself comes over and may
be received as usual: if the phial in which the
gas is generated be warmed to 140 or 150°,
the gas is given out more readily. A half
ounce phial with 20 grains of phosphuret in
small lumps, will produce 3 or 4 cubic inches
of gas. If the phosphuret of lime has been
previously exposed for a few hours to the at^
mosphere, the gas is more abundant, but con-
sists chiefly of hydrogen, mixed with a little
phosphuretted hydrogen.
Pure phosphuretted hydrogen is distin-
guished by the following properties : 1. It ex-
plodes when coming into the atmosphere in
bubbles, and a white ring of smoke subse-
quently ascends: 2. It is unfit for respiration,
and for supporting combustion : 3. Its spe-
cific gravity is 1.1 nearly, that of atmosphe-
ric air being unity: 4. Water absorbs fully .J.
of its bulk of this gas, which is expelled
again by ebullition or by agitation with other
gases, but not without some loss : 5. A small
portion being electrified for some time, de-
HYDROGEN. 171
posits abundance of phosphorus, and expands
from one volume to ly nearly, which is found
to be pure hydrogen: 6. Liquid oxymuriate
of lime absorbs phosphuretted hydrogen, con-
verting it into phosphoric acid and water,
and leaves any free hydrogen that may be
present; hence we are enabled to ascertain
the proportion of free hydrogen in any such
mixture, an important point as far as regards
this gas: 7. One volume of pure phosphu-
retted hydrogen, requires two volumes of
oxygen for its complete combustion by an
electric spark, in Volta's eudiometer; (the
gases must be previously mixed in a tube not
more than XV °f an incn m diameter, to pre-
vent an explosion in the act of mixing, after
which they may safely be transferred into any
other vessel); the result of the combustion
is phosphoric acid and water: 8. One volume
of phosphuretted hydrogen, mixed with from
2 to 6 volumes of nitrous gas, may be ex-
ploded by electricity in Volta's eudiometer;
or it may be exploded by sending up a bub-
ble of oxygen, without electricity ; in like
manner, may the mixtures of phosphuretted
hydrogen and oxygen be exploded by a bub-
ble of nitrous gas: 9. One volume of phos-
phuretted hydrogen, mixed with 4, less or
more, of nitrous oxide, is also explosive by
172 PHOSPHURETS.
electricity, but the mixture undergoes no
change without electricity, at least in a day :
10. Mixtures of phosphuretted hydrogen and
nitrous gas have a slow chemical action, by
which in from 1 to 12 hours, the phosphuretted
hydrogen is burnt and the nitrous gas decom-
posed into nitrous oxide and azotic gas: 11.
According to Sir HL Davy and Dr. Thomson,
phosphuretted hydrogen gas being heated along
with sulphur in a dry tube, the gas is decompo-
sed and a new gas, sulphuretted hydrogen, is
formed, and the phosphorus unites with the sul-
phur. Davy says the gas is doubled in volume
by this operation ; but Thomson says it remains
the same; some doubt therefore exists res-
pecting this fact: 12. When phosphuretted
hydrogen gas is let up to oxymuriatic acid
gas, a quick combustion with a yellow flame
is observed, ' and the result varies according
to the proportions: when one volume phos-
phuretted hydrogen is put to 3 or 4 of acid
gas, both of the gases disappear, and muri-
atic and phosphoric acids are produced.
As these properties differ in many respects
from those hitherto assigned to this gas, it
will be necessary to enlarge upon them. The
sp. gr. of this gas has already been adverted
to, (Vol. 1.), and its great variation from
.3 to .85; more recently Dr. Thomson finds
HYDROGEN. 173
it about .9. In all these instances it was, I
have no doubt, contaminated with less or
more of hydrogen ; at least it was so in my
own instance ; for, I have the proportion of
oxygen which it required for its complete
combustion, both before and after it was
weighed. It was what I then thought pure
gas: that is, 100 volumes required nearly 150
of oxygen ; but I am now convinced that gas
of this description contains ^- of its volume
of free hydrogen; hence the correction of the
sp. gravity. Davy estimates the sp. gr. of the
gas which he denominates hydrophosphoric at
.87 or 12 times that of hydrogen; this gas, as
will appear from this and other properties, is
in all probability phosphuretted hydrogen gas,
nearly pure.
The absorption of this gas by water, has
been stated variously. In 1799 M. Raymond
found that water absorbs rather less than | of
its volume of this gas : in 1802, Dr, Henry
rates its absorption at ~T only; in 1810 I
found it ^T; in 1812, Davy found it (hydro-
phosphoric gas) to be ~; in 1816, Dr. Thom-
son found it to be ^T ; I now estimate it as
stated above at £. These enormous differen-
ces may be partly accounted for by varieties
in the gas; and partly from the theory of the
absorption not being understood; but these
174 PHOSPHURETS.
are scarcely sufficient excuses in all the cases.
I find that my early experiments on the ab-
sorption of phosphuretted hydrogen by water,
were made prior to the discovery of the me-
thod of analysing* the gas by electric combus-
tion; consequently they were deficient in re-
gard to the quality of the gas, both before
and after agitation ; the best gas that ever I
had, was such as took 150 oxygen per cent,
for its combustion, exclusive of any common
air; and it was often such as to require con-
siderably less. The bottle which I used for the
purpose in 1810 contains 2700 grains of wa-
ter; at first I charged water with hydrogen;
into this 120 grain measures of phosphuretted
hydrogen were put, and the whole well agi-
tated: there were left 98 measures; — this
proved that the gas was more absorbable than
hydrogen : into the same water were put 98
more phosphuretted hydrogen and agitated ;
out, 80; this confirmed the proof: Into the
same water were put 97 hydrogen and agitated
well; out 105: This shewed that the hydrogen
had expelled a part of the gas again, and was
less absorbable of the two. As the pheno-
mena were much the same as if oxygen had
been used instead of phosphuretted hydrogen,
it was concluded to have the same absorb-
ability.
HYDROGEN. 175
In the present instance, however, I have
been more circumstantial; after repeatedly
agitating" water with pure azotic gas, so as to
saturate it and expel the oxygen, I then put
in 110 grain measures of phosphuretted hy-
drogen composed of 100 pure gas, 5 hydro-
gen, and 5 azotic gas or rather atmospheric
air. After due agitation, all was absorbed
but 35; this was mixed with a known portion
of oxygen and exploded ; the diminution was
19 measures; the oxygen remaining was de-
termined by hydrogen ; from which it appear-
ed that 10 combustible gas had taken 9 oxy-
gen. Now 10 being f- of 35, we may consi-
der the water as |i impregnated with the
phosphuretted hydrogen, and |:; with azote;
but as there were 105 combustible gas and
only 10 left, 95 must have entered the water
and caused it to be ^ charged with the gas;
whence we may infer that 332 gas would
have been a full charge for 2700 water, which
is almost exactly ~, as stated above. Other
experiments gave corresponding results. On
admitting 51 azotic gas to the water, and agi-
tating it a good deal for 4 or 5 minutes, there
came out 51 measures or the same volume:
this was found in the same way to consist of
43 azote and 8 combustible, which took 10
oxygen. Again 51 azote was agitated in the
176 PHOSPHURETS.
water, and there came out 51, of which 5 +
were combustible and took 9 oxygen. After
this the bottle of water was put into a pan of
water which was raised to the boiling" heat,
a bent tube filled with water being adapted to
the water bottle, and having its end immer-
sed in water: by this operation gas was ex-
pelled from the water, and caught in the neck
of the bottle; when it amounted to 22 grain
measures it was transferred and was found
to consist of 17 azote +5 combustible, which
took 10 oxygen. By these experiments we
see that the gas is expelled again from the
water, both by ebullition and by other gases,
nearly the same in quality, but much dimi-
nished in quantity, the reason of which is not
very obvious. The liquid now required 30
measures of oxymuriate of lime, equivalent to
100 measures of oxygen, before it was satura-
ted ; that is, there appeared to be 50 phos-
phuretted hydrogen remaining in the water.
Adding a little lime-water threw down a very
sensible quantity of phosphate of lime.
The expansion of phosphuretted hydrogen
by electricity is a subject on which there has
been as much diversity as on its absorption.
In 1797, Dr. Henry found that it expanded
" equally with carbonated hydrogen/' (Philos.
Trans). In 1800, Davy states that phosphu-
HYDROGEN. 177
retted hydrogen was not altered in volume
by electricity. (Researches, page 303.) In
1810, my experiments led me to adopt the
same conclusion. In 1811, Gay Lussac found
(Recherches, page 214), that potassium heat-
ed in phosphuretted hydrogen gas, expanded
100 volumes to 146; he infers that the true
expansion ought to have been to 150. In 1812,
Davy observes, that when electric sparks are
passed through gases of this kind, " usually
there is no change of volume." (Elements of
Chem. Philos. p. 294.) But he adds that
when a gas (sp. gr. 6, hyd. being 1) was heat-
ed with zinc filings over mercury, there was
an expansion of volume of more than -J-
Also potassium heated in it, made 2 parts be-
come 3 or 3, parts rather more than 4, (1810) ;
the residual gas in these cases was pure hydro-
gen. Hydrophosphoric gas (sp. gr. 12) yield-
ed 2 volumes of hydrogen, by heating potas-
sium in it. In 1816, Dr. Thomson found that
by electric sparks phosphorus was deposited,
and hydrogen remained " exactly equal to the
original bulk of the phosphuretted hydrogen/'
Lastly, in 1817, I found by two experiments,
that by electrifying 30 grain measures of
phosphuretted hydrogen in a tube over water,
uninterruptedly for nearly 2 hours, I produ-
ced an expansion of ^, or the gas became 36
VOL. II. Z
178 P.HOSPHUllETS.
measures; originally the gas contained 2f
common air, and the rest was combustible so
that 100 measures took 190 oxygen. By ex-
ploding the residue with oxygen, I .found, that
-}T or ^V of the phosphuretted hydrogen, still
remained undecomposed. Taking these ob-
servations into consideration along with the
fact;,; that 1 volume of the purest gas requires
2 of oxygen for its combustion, I conclude
that;,the true expansipn should bei-, or 3 vo-
lumes of gas should become 4, and then it
will be found that 4- pfj the oxygen is joined
to the hydrogen and? -| to the phosphorus,
which accords with what appears to me the
only correct view of the constitution of phos-
phoric acid, namely, % atoms of oxygen to 1
of phosphorus.
The action of oxy muriatic acid, whether
free or combined, on phosphuretted hydrogen,
is curious and interesting; in. both cases it
effects a complete and instantaneous combus-
tion of both phosphorus and hydrogen; when
the acid is put to in the state of gas, it not
only burns the phosphuretted hydrogen, but
any free hydrogen, that niay be present; , but
X]^h jias, a limit: if the phosphuretted hydro*
gen. be largely diluted (90 per cent.) with hy-
d^pg^en, this last is> jW.Jjplly left; the reason
^eein^to be, jthe.pfyo^phur^tted hy^rogeu burns
HYDROGEN. 179
at a lower temperature; and hence probably
it is, that liquid oxymuriate of lime burns the
phosphuretted hydrogen, but not the hydro-
gen gas.
The quantity of oxygen necessary to satu-
rate a given volume of phosphuretted hydro-
gen is easily found. Oxygen gas containing
a known per centage of azotic gas, must be
used in some excess, mixed with a due por-
tion of the gas. After exploding the mix-
ture, the loss must be observed, and then the
remaining oxygen must be found by exploding
it with hydrogen. Hence the true volume of
oxygen spent by the first explosion, and that
of the combustible gas are both determined.
The due proportion of oxygen is so nearly 2
to 1, that I have not been able to determine
on which side the truth lies. Dr. Thomson
says that when phosphuretted hydrogen and
oxygen are mixed, two volumes to one, a white
smoke takes place, the volume of oxygen
gradually disappears, and there remains be-
hind a quantity of hydrogen exactly equal to
the original volume of the phosphuretted hy-
drogen. I have observed nothing at all like
this. A mixture of phosphuretted hydrogen
and oxygen stood 24 hours without sensible
diminution, and afterwards being- exploded,
2 volumes of oxygen disappeared fori of phos-
180 PHOSPHURETS.
phuretted hydrogen, the same as would have
done at the moment of mixing. Perhaps the
temperature may have some influence; mine
was about 55°.
I have tried the minimum of oxygen that
will consume or dissipate phosphuretted hy-
drogen gas. It may be exploded with about
i of its volume of oxygen, with the same
phenomena as Davy observed of the hydro-
phosphoric gas. Phosphorus is thrown down
and a volume of combustible gas is left about
10 per cent, greater than the original volume
of phosphuretted hydrogen. This gas is nearly-
pure hydrogen. Hence the whole gas may
be dissipated at 2 successive explosions, by
rather less than an equal volume of oxygen.
If phosphuretted hydrogen be exploded with
an equal volume of oxygen, phosphorous
acid, water and a little phosphoric acid are
formed, and some hydrogen remains.
One of the most remarkable properties of
phosphuretted hydrogen, is that announced
by Dr. Thomson, namely, its combustion with
nitrous gas by electricity ; and the slow com-
bustion by the same gas, which 1 have men-
tioned above is a fact still more difficult to ex-
plain. I tried the combustion of phosphu-
retted hydrogen by nitrous gas and electri-
city in 1810, but did not succeed. The rea-
HYDROGEN. 181
son was, the gas was not sufficiently pure. No
phosphuretted hydrogen that is not 70 or 80
per cent, pure, can, I imagine, be exploded by
nitrous gas; even the purest requires sometimes
more than one spark, when mixed in the most
favourable proportions; and I have known in-
stances in which the mixture has exploded af-
ter electrification for a few minutes. An excess
or defect of nitrous gas, occasions oxygen or
hydrogen to be found in the residual gas, just
as when we explode with oxygen. One vo-
lume of phosphuretted hydrogen requires, as
nearly as I can find, 3| of nitrous gas for mu-
tual saturation . The azote developed amounts
to 1| volumes or rather less, (due allowances
in all such cases being made for that already
existing in the two gases* )
The mutual action of nitrous gas and phos-
phuretted hydrogen without electricity exhi-
bits one of the most singular phenomena we
have in chemistry. Nitrous gas seems con-
stantly to be decomposed, one part producing
nitrous oxide and another part azote, even
though an excess of nitrous gas remain unde-
composed in the mixture, and both the phos-
phorus and hydrogen are completely burnt;
but if the nitrous gas be deficient, then nitrous
oxide, azote, and some of the phosphuretted
hydrogen are found in the residue, and the
182 PHOSPHURETS.
rest of the phosphuretted hydrogen is com-
pletely burnt or converted into phosphoric
acid and water; hei'e appears no preference
of phosphorus to hydrogen in this case, nor
any partial combustion. From an attentive
consideration of the results of several expe-
riments, I am inclined to offer the following
solution of this remarkable case : One atom
of phosphuretted hydrogen attacks 5 of ni-
trous gas at the same instant; the atom of
phosphorus takes 2 of oxygen, and gives the
corresponding 2 of azote to the two of nitrous
gas, and thus makes two atoms of nitrous ox-
ide, while the hydrogen takes 1 of oxy-
gen from the fifth atom and liberates the
azote; thus 2 measures of nitrous oxide are
formed along with 1 of azote; and they are
generally found in the residue in that ratio.
The azote does not seem to pass through the
intermediate state of nitrous oxide; for, as
soon as the nitrous gas ceases to exist, there
is an end of the combustion.
It may be proper to advert more particu-
larly to the hydrophosphoric gas of Davy.
That this gas is the same as that we have
been describing, can hardly admit of a doubt.
Their near agreement in sp. gr., in their ab-
sorbability by water, in the quantity of oxy-
gen requisite for their combustion, in their
HYDROGEN. 183
moderate expansion by burning" with a mini-
mum of oxygen and in their combustibility by
oxy muriatic acid, are circumstances suffici-
ent to warrant their identity. It is said that
by heating potassium in this gas, one volume
yields two of hydrogen ; but it has not been
found to yield two volumes by electricity,
the more accurate criterion. Besides, both
Davy and Gay Lussac find that potassium
heated in the more common phosphuretted
hydrogen expands it from 1 to li- or If volume,
which common electricity will not do; it is
presumed therefore that the potassium in some
way conduces to the production of a portion
of the hydrogen. Spontaneous Ignition or
explosion is, I believe, no distinctive mark
of variety in phosphuretted hydrogen; when
this gas is produced, it is usually explosive
from the uncombined phosphorus which it
elevates; but the best and purest phosphu^
retted hydrogen loses the property wholly or
partially by standing a while over water,
.though it loses no sensible part of its phos-
phorus.
. It is commonly stated that phosphuretted
hydrogen deposits phosphorus by long stand-
ing.. This seems to be true; .but the deposi-
tion is flower than I imagined. Seven years
ago I set jaside a bottle of impure phosphu-
184 PHOSPHURETS.
retted hydrogen whicji I then labeled, 10
combustible take 14.6 oxygen; this bottle has
not been preserved with special care to se-
clude the atmosphere ; notwithstanding that,
it is now such, that 10 combustible take 6.7
oxygen, and hence it still contains some ge-
nuine phosphuretted hydrogen.
2 and 3. Phosphurets ofcarbone and sulphur.
See Vq:l. 1 . page 464.
4. Phosphuret of lime.
This compound may be formed by sublim-
ing phosphorus in a glass tube containing
small fragments of recently calcined lime,
heated to a low red. The sublimed phospho-
rus coming into contact with the hot lime,
the two unite with a vivid glow, and in due
time mutual saturation is produced. The re-
sult is a dry, hard compound of a deep brown
or reddish colour, which on cooling must be
put into a bottle and well corked, if not in-
tended for immediate use, as it soon changes
by the action of atmospheric air and moisture.
With this precaution, I have reason to think
it may be kept unimpaired for years.
LIME. 185
As far as I know, no experiments have
been published relating to the proportion in
which phosphorus and lime unite. M. Du-
long, in a valuable paper on the combina-
tions of phosphorus and oxygen, in the
3Iemoires de la Societe d'Arcueil, Vol. 3.
(1817,) has given some account of his ex-
periments on the earthy phosphurets; but
it is to be regretted that he has given none on
the proportions of their elements.
In order to ascertain the phosphorus, I put
10 grains of well preserved phosphuret of lime,
into 1000 grains of liquid oxymuriate of lime,
such that by previous trials I knew would im-
part 3.5 grains of oxygen; to this mixture a
quantity of muriatic acid was put, sufficient
to engage the lime; the phosphuretted hydro-
gen disengaged, was of course made to pass
through the liquid as it was generated, and be-
came oxidized, so as to lose its gaseous form ;
the surplus gas was prevented from escaping
by an inclination of the bottle; it was 45
grain measures only, and of this 30 were found
to be pure hydrogen, and the rest atmosphe-
ric air detached from the water; these 30
measures were the free hydrogen, which would
have been mixed with the phosphuretted hy-
drogen, in the ordinary way. In due time,
the whole of the phosphuret of lime was dis-
vol. it. a a
186 PHOSPHURETS.
solved. The liquid was strongly acid, and
manifested no smell of oxymuriatic acid, a
proof that it was all decomposed. , To this
were added 70 more of the oxy muriate of
lime before' the smell of it was permanently
developed. The liquid was next saturated
with lime-water, and the phosphate of lime
carefully collected and dried ; when heated to
alow red it weighed 12 grains, and consisted,
according to my estimate of this compound,
of 6 — grains of phosphoric acid and 6 +
grains of lime. The 6— grains of acid con-
tained 2.4 phosphorus and 3.5 of oxygen. It
must he remembered that 10 grains of phos-
phuret yield about 500 measures of phosphu-
retted hydrogen, and these contain 650 mea-
sures of hydrogen, which last is also oxidized
at the expence of the oxymuriatic acid;, but
then there is an equivalent of oxygen from
the water, so that this does not influence the
calculation for oxygen. There appears then
to be only an excess of .24 grains of oxygen
unaccounted for, (arising from the additional
70 of oxymuriate of lime), which is as little
as can be expected in such an experiment. If
the phosphorus amount to 24 per cent, we
may reasonably infer that the remainder (76)
is mostly lime, though I have not been able
t@ detect above 60. Now if an atom of phos-
LIME. 187
phorus weigh 9| and one of lime 24, the due
proportion of the protophosphuret of lime
would be 28 phosphorus and 72 lime; but
when the article is made for sale, it is more
likely to find a defect than an excess of phos-
phorus.
According to Dulong, when the earthy
phosphurets are decomposed by water, phos-
phuretted hydrogen and subphosphorous acid
are formed. I believe this determination is
right; for T find at most only 4 of the above
proportion of phosphorus in the phosphuret-
ted hydrogen yielded by 10 grains of the
phosphuret of lime ; the remaining \ seem to
rest in the liquid in combination with the oxy-
gen and lime; that is, 1 atom of hydrogen
combines with 1 of phosphorus, and 1 of
oxygen with 2 of phosphorus. Notwith-
standing this, the phosphoric acid produced
from the residue by means of ox y muriate of
lime, does not in general correspond to the
above quantity. Perhaps this loss may be
owing to the phosphorus carried over in me-
chanical suspension by the gas.
M. Dulong observes, that even the earthy
subphosphites are very soluble; this did not
appear to me to be the case with that of lime :
10 grains of phosphate of lime, that had
been exposed for 20 minutes to the air, were
188 PHOSPHURETS.
put into a gas bottle filled with 400 grains of
water; this was kept at nearly the boiling
heat for an hour, when 725 grain measures of
gas were produced, and some phosphorus was
carried over with it into the receiving bottle and
bason of water. The gas being analysed, was
found to consist of 62 per cent, phosphuret-
ted hydrogen, 33 hydrogen and 5 common
air. The 400 grains of water in Hie gas bot-
tle treated with oxy muriate of lime, and then
with lime water, scarcely gave any appreci-
able quantity of phosphate of lime. The
insoluble residue when dried yielded 9 grains.
This dissolved in muriatic acid left a fraction
of a grain of dirty yellow powder, which in-
dicated some phosphorus; and the muriate of
lime indicated about 6 grains of lime.
5. Phosphuret of baryies.
The combination of phosphorus and bary-
tes may be effected in the same way as the
foregoing, and the compound has the same
appearance. According to Dulong, who has
examined this phosphuret with particular at-
tention, it gives out phosphuretted hydrogen
when dropped into water, the same as that
of lime. When the gas ceases to be giren
BARYTES. . 189
out, a powder remains completely insoluble
in water, of a variable colour, yellow, grey
or brown. It is not altered by the air ; but
it gives out a slight phosphoric flame when
heated. Dilute nitric or muriatic acid, dis-
solves nearly the whole with a trace of phos-
phuretted hydrogen, and leaves only a few
atoms of greenish yellow powder, soluble in
oxymuriatic acid. The part dissolved by the
acids being precipitated by ammonia, gives
phosphate of barytes. From these facts he
infers that the residue insoluble in water, con-
sists of a small portion of phosphuret of ba-
rytes with excess of base, and phosphate of
barytes. The water in which the phosphu-
ret was decomposed, contains most of the
barytes; carbonic acid produces a slight pre-
cipitate, and then leaves a neutral liquid
containing the subphosphate of barytes, which
appears to be a very soluble salt. Sulphuric
acid throws down the barytes and leaves the
subphosphorous acid in the liquid.
Nothing certain is determined from experi-
ment respecting the proportion of phosphorus
and barytes which combine; but from analogy
it is probable that they combine atom to atom,
or 68 parts barytes with 9 of phosphorus; or
100 parts of the compound contain 88 of ba-
rytes and 12 of phosphorus.
190 PHOSPHURETS.
6. Phosphuret of strontites,
Phosphuret of strontites may be formed as
the two preceding- articles. It is in all res-
pects similar to the phosphuret of barytes
according to Dulong, and its properties there-
fore need not be particularized.
From analogy, I should apprehend, it must
be constituted of 46 strontites and 9 phos-
phorus, or one atom of strontites to one of
phosphorus; that is, 100 parts of phosphuret
should contain 83 strontites and 17 phos-
phorus.
Combinations of the other earths and phos-
phorus have not yet been effected. Neither
have the alkalies been combined with phos-
phorus: the hydrates of these as well as those
of the earths, yield phosphuretted hydrogen
^vhen heated with phosphorus, and probably
a phosphate or subphosphate of the base.
Iff. Sementini of Rome is said to have suc-
ceeded in combining potash and phosphorus
by means of alcohol. His experiments, how-
ever, appear to me too indefinite to warrant
the conclusion. (See An. of Philos. — 7. p.
280). The compounds of phosphorus with
potassium and sodium are described in the
sequel, amongst the metallic phosphurets.
GOLD. 191
7. Phosphuret of gold,
M . Pelletier heated together in a crucible,
half an ounce of pure gold, one ounce of
phosphoric glass and -§■ of an ounce of pow-
dered charcoal, the heat was raised suffi-
ciently to fuse the gold. Phosphoric fumes
arose, but the whole of the phosphorus was
not dissipated. The gold remaining was
whiter than natural, and brittle under the
hammer. Exposed to a very high heat it lost
^ of its weight, and resumed the ordinary
characters of gold.
The same chemist heated 100 grains of
pure gold in filings to a bright red; he then
projected small fragments of phosphorus
amongst the gold successively till after it had
entered into fusion. The gold preserved its
colour, but became brittle under the hammer
and granular in the fracture; it had increased
4 in weight.
Mr. Edmund Davy, by heating in a tube
deprived of air, finely divided gold and
phosphorus, effected a combination of them.
It had a grey colour and metallic lustre. The
heat of a spirit lamp was sufficient to decom-
pose it. It contained about 14 per cent, of
192 PHOSPHURETS.
phosphorus. (Davy's Chemistry, page 448 —
An. 1812).
Oberkampf and Thomson have succes-
sively observed the precipitation occasioned
by water impregnated with phosphuretted
hydrogen, in solutions of muriate of gold,
The former of these has some interesting re-
marks on the phenomena. When a current
of this gas is passed through a dilute solution
of muriate of gold for a time, and then sud-
denly discontinued, the solution becomes
brown and passes soon to a fine deep purple.
A yellowish brown precipitate is obtained,
which is metallic gold, and the liquid, now
become yellow again, contains muriate of
gold and phosphoric acid. The experiment
may be continued with the like results. But
if the liquid be saturated with gas before any
precipitate is suffered to subside, a black pow-
der is obtained which does not seem to con-
tain any metallic gold, and the liquor ceases
to have any colour. This black powder is the
phosphuret of gold ; exposed to heat it in-
flames and leaves metallic gold, but its ele-
ments are not separable by mechanical means.
(An. de Chimie, 80—146, for 1811).
Water impregnated with the gas was found
to have like effects as the gas itself. Whence
GOLD. 193
Oberkampf concludes that as long as an ex-
cess of gold remains in solution, the phosphu-
retted hydrogen precipitates the metal only;
but when the gas is in excess, the phospho-
rus leaves the hydrogen and unites with the
precipitated gold.
I should rather suppose that the precipita-
tion of the gold may be, in part at least, ow-
ing to the free hydrogen which we now know
accompanies the phosphuretted hydrogen
largely, in the manner in which this gas was
formerly procured ; however that may be, I
find that water, impregnated with the purest
phosphuretted hydrogen, has the property of
precipitating the black phosphuret of gold
from the muriate of that metal, in such man-
ner as to effect complete mutual saturation,
leaving nothing in the liquid but the muriatic
acid. Let a solution containing a known
quantity of gold be gradually dropped into
water, containing a known quantity of phos-
phuretted hydrogen, as long as any black pre-
cipitate is formed. The point of saturation
will be found when 60 parts by weight of gold
have united to 9 of phosphorus, nearly; or
when one atom of gold has united to one of
phosphorus. Hence it may be concluded that
100 grains of the phosphuret of gold contain
13 or 14 of phosphorus, which agrees very
VOL. II* B b
194 PHOSPHTJRETS.
nearly with the results of Mr. Edmund Davy
abovementioned.
8. Phosphuret of platina.
M. Pelletier succeeded in combining1 pla-
tina with phosphorus by the same methods as
with gold. By projecting* phosphorus on
grains of platina heated to a strong red, the
latter acquired an increase of weight of 18 on
the hundred; but this was probably an excess,
as some vitreous phosphoric acid was found
mixed with the mass.
In the Philos. Magazine, Vox,. 40, Mr. E.
Davy has related some experiments made
with a view to combine platina and phospho-
rus ; he effected it by heating platina and
phosphorus together in an exhausted tube;
the union commenced below a red heat and
was attended with vivid ignition and flame.
The compound was of a blueish grey colour
and consisted of 82| platina and 17| phos-
phorus according to his estimate. Also by
heating the ammonia-muriate of platina with
^ of its weight of phosphorus in a retort over
mercury, muriatic gas was liberated, and mu-
riate of ammonia and phosphorus were sub-
limed, but there remained at dull red heat an
SILVER. 195
iron black or dark grey mass at the bottom, of
the sp. gr. 5.28. It was estimated to consist
of 70platinaand 30 phosphorus ; but I doubt
whether it could consist of these two ele-
ments only.
Phosphuretted hydrogen water scarcely
has any effect on muriate of platina. After
some time a very light flocculent matter ap-
pears, as Dr. Thomson has observed; but this
seems to me to be nothing but a slight preci-
pitation of phosphorus alone ; I apprehend the
gas unites with the platina, but the compound
remains in solution somewhat in the same
manner as platina and sulphuretted hydrogen.
The platina may be precipitated from the
clear liquid by muriate of tin, much the same
in appearance as if no phosphuretted hydro-
gen were present.
9. Phosphuret of silver.
When pieces of phosphorus are dropped
amongst silver heated to red in a crucible, the
two unite and enter into fusion, according to
Pelletier; when the metal is saturated with
phosphorus the whole continues in a state of
tranquil fusion; but being withdrawn from
the fire, at the moment of congelation, a
196 PHOSPHURETS.
quantity of phosphorus becomes suddenly vo-
latile and burns vividly, and the surface of
the metal becomes uneven. The metal on
being cooled, is found to have gained from 12
to 15 per cent. ; and he apprehends that when
fluid it contains 10 per cent, more, making
in all 25 phosphorus to 100 silver.
The phosphuret of silver is white and crys-
talline, brittle under the hammer, but capa-
ble of being cut with a knife. By a strong
heat the phosphorus is dissipated and leaves
the silver pure.
Both Raymond and Thomson observe that
phosphuretted hydrogen water precipitates
silver from its solutions of a black colour. I
find that a solution of sulphate of silver con-
taining one grain of the metal, requires wa-
ter containing 90 grain measures of phosphu-
retted hydrogen to saturate it; the whole of
the silver falls readily and leaves nothing but
the acid in the water. Now the weight of 90
measures of this gas is nearly i- of a grain ;
hence the proportions of metal and phospho-
rus are as 10 to 1, which shows that they
combine atom to atom, or 90 silver to 9£
phosphorus. This is somewhat less of phos-
phorus than is determined above by Pelletier.
MERCURY. 197
10. Phosphuret of mercury.
M. Pelletier made several attempts to com-
bine phosphorus and mercury. He seems to
have succeeded best, by exposing mercury
in an extreme state of division, to phosphorus
under water in a moderate heat. The phos-
phuret is a black compound, which is resolved
again into its elements by distillation.
When nitrate of mercury is treated with
phosphuretted hydrogen water, a copious
dark brown or black precipitate is instantly
formed, as Raymond and Thomson have ob-
served. This black precipitate, Raymond
adds, soon becomes white and crystalline in
passing from phosphuret to phosphate, by at-
tracting oxygen.
I have found the black powder when dried
in a moderate heat to abound in small shining
globules, which have all the appearance of re-
vived mercury. However this may be, I find
that a certain weight of mercurial salt re-
quires a certain portion of gas to saturate it,
so as that the whole mercury shall be preci-
pitated. One grain of mercury requires rather
more than -^ of its weight or 50 grain mea-
sures of the gas for its saturation. This proves
198 PHOSPHURETS.
the combination to be the most simple, or atom
to atom ; that is, 167 mercury take 9| phos-
phorus; or 100 mercury take 5J phosphorus
nearly.
11. Phosphuret of palladium.
When nitrate of palladium is dropped into
phosphuretted hydrogen water, a copious
black flocculent precipitate is immediately
formed, which doubtless consists of palla-
dium and phosphorus.
Into 800 grains of phosphuretted hydrogen
water containing 20 grain measures of gas,
were put by degress 22 grain measures of
muriate of palladium (sp. gr. 1.01) contain-
ing .12 acid and .14 oxide, corresponding to
.12+ metal; mutual saturation was produced,
and a finely distinct black powder precipita-
ted, leaving the water clear and colourless,
which was found by lime-water to contain .12
parts of a grain of muriatic acid. The black
powder collected and dried, corresponded as
nearly as could be determined in weight to
the ingredients. Now 20 measures of gas
would weigh .025 of a grain, of which .0025
would be hydrogen and .0225 phosphorus;
whence we have .12-f metal joined to .0225
COPPER. 199
phosphorus or 50 to 9 nearly, indicating one
atom of each. Hence 100 palladium would
take 18 or 19 phosphorus.
12. Phosphuret of copper.
M. Pelletier combined copper and phos-
phorus by the same means as the preceding
compounds. One hundred grains of copper
united by heat with 15 of phosphorus; the
fused mass when cooled was white and very
hard. As part of the copper gets oxidized
during the process he thinks it probable, with
M. Sage, that copper may acquire 20 per
cent, of phosphorus.
In the 3d Vol. of Memoirs of the Soci-
ety of Arcueil, page 432, M. Dulong con-
verts fine copper wire into phosphuret by
heating it to a low red, and passing the va-
pour of phosphorus over it in hydrogen gas.
In the sequel he observes that 10 grammes
of phosphuret of copper contained 1.97 of
phosphorus; that is, the copper was to the
phosphorus as 8.03:1.97, or as 100:24.5.
This exceeds much Pelletier's result, and is,
I think, too high. For, he found that the
above phosphuret converted into phosphate of
copper by nitric acid yielded 14.44 grammes.
Now supposing the atom of phosphorus to
200 PHOSPHURETS.
weigh 9|, that of phosphoric acid 23|, and
that of the black oxide of copper 70, we
have an atom of phosphate of copper = 93-^- :
and if 93| : 9| :: 14.44 : 1.444, for the phos-
phorus in 10 grammes; and hence the copper
would be 8.556: this would give 100 copper
to 17 phosphorus nearly, which would accord
well with Pelletier's determination, and very
nearly agree with the theoretic result of 100
copper to 16^ phosphorus.
Both Raymond and Thomson remark that
phosphuretted hydrogen water produces a
black or dark brown precipitate in sulphate of
copper. I have not found any precipitate
from any of the salts of copper by the same
means. But if the blue hydrate be first pre-
cipitated by lime water, and then the phos-
phuretted hydrogen water admitted, the hy-
drate is immediately converted into a dark
olive, which in all probability is a phosphuret
of copper. From some experiments I am in-
clined to believe that this compound is the
deutophosphuret, or two atoms of phosphorus
to one of copper; and hence the copper is to
the phosphorus as 100 : 33^.
IRON — NICKEL. 201
13. Phosphitret of iron.
M. Pelletier formed a phosphuret of iron by
both the methods above described for gold.
He describes the phosphuret as very hard^» of
a white colour, striated and magnetic. He
estimates, with some uncertainty, that 100
iron may combine with 20 phosphorus.
Berzelius produced a phosphuret of iron by
reducing the phosphate of the metal by char-
coal and heat. (An. de Chimie, July 1816).
He describes it as having the colour of iron,
brittle and slightly acted upon by the magnet.
By his analysis it was constituted of 100 iron
and 30 phosphorus. The true proportion
probably would be one atom to one, or 25 iron
to 9~ phosphorus ; that is, 100 iron to 37 phos-
phorus.
Both Raymond and Thomson found that
sulphate of iron yields no precipitate by phos-
phuretted hydrogen water; and I may add,
that the precipitated oxide or hydrate is also
unaffected by the same.
14. Phosphuret of nickel.
By projecting phosphorus amongst red hot
nickel, Pelletier united 20 parts of the former
to 100 of the latter. A part of the combined
VOL. II. C C
202 PHOSPHURETS.
phosphorus, he observes, flies off on cooling,
so that the above proportion may perhaps be
too low. Theoretically one atom of nickel
should combine with one of phosphorus ; that
is,#26 with 9^, or 100 with 36.
I find that neither the nitrate of nickel nor
the hydrate are affected by phosphuretted hy-
drogen water.
15. Phosphuret of tin.
MargrafF was the first who combined phos-
phorus and tin by fusing the metal along with
fusible salt from urine (phosphate of am-
monia). Pelletier succeeded also in this way,
as well as by the direct one of projecting
phosphorus into melted tin. The compound
was of a white colour; it gained 12 per cent,
of weight ; but as part of the tin was oxidized
and adhered to the crucible in form of glass,
he conjectures that tin would take from 15 to
20 per cent, of phosphorus. The atom of tin
being 52, and that of phosphorus 9|, the due
proportion would be 100 tin to 18 phosphorus.
Phosphuretted hydrogen water does not
seem to precipitate tin from solutions, nor yet
to act upon the precipitated oxide.
i/eait. 203
16. Phosphuret of lead.
Lead combines with phosphorus by the
same methods as tin ; but it is difficult to as-
certain the proportions, according to Pelletier,
from the oxidation and vitrification of part of
the lead. Muriate of lead distilled with fusi-
ble salt of urine, also yielded phosphuret of
lead. He conjectures the increase by phos-
phorus to be 12 or 15 per cent. ; but by theory
it should only be 10 or 11 per cent.
Raymond says that the nitrate of lead is
decomposed by phosphuretted hydrogen wa-
ter, but with less force than salts of silver and
mercury ; and that a phosphuret of lead is
formed, of which he gives no character, except
that it becomes in time a phosphate. Thom-
son says a slight white powder is formed by
the mixture. This was the case with me;
but I suspected that the white powder was
merely a little sulphate of lead, arising from
the impurity of the (rain) water ; and this was
found to be the fact; for the milkiness was
just the same with likfe water unimpregnated
with the gas. Besides, after the phosphuret-
ted hydrogen water has been saturated with
nitrate of lead till no more effect is produced,
still the water retains its peculiar smell, and
204 PHOSPHURETS.
a copious black precipitate is instantly produ-
ced by nitrate of silver or mercury. It ap-
pears then that phosphuret of lead cannot be
formed' this way . N either does phosphuretted
hydrogen water seem to have any effect on the
recently precipitated oxide of lead.
17. Phosphuret of zinc.
Both zinc and its oxide seem to combine
with phosphorus, according to Pelletier; but
the proportions were not ascertained. By
theory, zinc should take 32 per cent, of phos-
phorus.
18. Phosphuret of potassium.
Some account was given by Davy, of the
combination of potassium and phosphorus in
essays from 1807 to 1810 ; and by Gay Lussac
and Thenard in others from 1808 to .1811.
According to Davy, when potassium and
phosphorus are heated together, they combine
in one uniform ratio of 8 to 3 nearly; and the
compound, when acted upon by muriatic acid,
gives out from .8 to 1 cubic inch of phosphu-
retted hydrogen gas, resulting from one grain
POTASSIUM. 205
of the former and 4 of a grain of the latter
substances combined. Also he observed that
half a grain of potassium decomposed nearly
3 cubic inches of phosphuretted hydrogen,
and set free more than 4 c«t>ic inches of hy-
drogen; the phosphuret seemed to be of the
same kind as the former, or that by direct
combination of the two elements.
Gay Lnssac and Thenard combined the
elements by heat; the potassium is scarcely
fused till the phosphuret is formed. The ex-
cess of phosphorus sublimes, and the phos-
phuret is always of a chocolate colour; the
proportions were not ascertained. By treat-
ing this phosphuret with warm water, a
quantity of phosphuretted hydrogen was uni-
formly given out, about 40 per cent, more
than the hydrogen which would have been
yielded by the potassium alone in water.
But if the phosphuret was treated with dilute
acid instead of water, then less gas was given
out than otherwise ; and the stronger the acid
the less gas, so as sometimes to reduce the
gas in volume to that yielded by potassium
alone. They also found, as Davy had done,
that potassium heated in phosphuretted hy-
drogen decomposed it, uniting with the phos-
phorus and producing the same compound as
in the direct way.
206 PHOSPHURETS.
The results of Davy and the French che-
mists appear to be discordant; but I appre-
hend they may be reconciled. It appears
probable from both, that the phosphuret of
potassium must be a compound of one atom
of each, or 35 potassium and 9-^ phosphorus ;
that is, 100 potassium and 27 phosphorus
nearly. Now in Davy's method of treating
the compound with acid, it is most probable
that the atom of potassium takes one of oxy-
gen to form potash, and the atom of phos-
phorus takes one of hydrogen to form one of
phosphuretted hydrogen; but 3 volumes of
pure phosphuretted hydrogen contain 4 vo*
lumesof hydrogen, (see page 178) ; and Davy
obtained nearly % of the volume of gas which
the potassium alone would have produced,
which therefore accounts for the fact as sta-
ted by him.
On the other hand, the French chemists by
treating the phosphuret with hot water, pro-
bably determined the resolution in this way :
the potassium resolved the water into oxygen
and hydrogen, the last of which was libera-
ted in a free state, and of course produced
the usual volume ; the phosphorus also resolv-
ed the water into oxygen and hydrogen, one
half of it taking the oxygen to form phos-
phorous acid, and the other half taking the
SODIUM — BISMUTH . 207
hydrogen to form phosphuretted hydrogen,
which of course would produce phosphuret-
ted hydrogen amounting to 4 of the volume of
free hydrogen or 38 per cent, nearly, which
would make up the volume of gas to 138, or
nearly 140, as observed by them. It is not
unlikely that 2 or 8 per cent, of hydrogen
might be added by the further decomposition
of water by the phosphorous acid, in order
to make it into phosphoric acid.
19. Phosphuret of sodium.
No particular experiments having been de-
tailed of this compound, we must infer it is
similar to the last mentioned, and consists of
one atom of sodium, 21, and one atom of phos-
phorus, 9y ; that is, 100 sodium and 44 phos-
phorus nearly.
20. Phosphuret of bismuth.
If we may judge from M. Pelletier's expe-
riments, bismuth has but a weak affinity for
phosphorus. By projecting portions of phos-
phorus amongst melted bismuth, he succeed-
ed in uniting some of it to the metal ; he es-
208 PHOSPHURETS.
timates the quantity at 4 per cent. ; whereas
by theory it ought to be 15 per cent, suppos-
ing them to unite atom to atom.
I do not find that the salts or oxide of bis-
muth are materially affected by phosphuretted
hydrogen water.
21. Phosphuret of antimony.
■
Phosphorus may be combined with anti-
mony, according to Pelletier, by the same
means as with the other metals. The phos-
phuret has a white, metallic appearance and
lamellar fracture. The ratio of the elements
was not determined. By theory supposing
one atom to unite with one, it would be 40
to 9^, or 100 antimony to 23 phosphorus
nearly.
Phosphuretted hydrogen water seems to
have no effect on the salts or oxide of antimony.
22. Phosphuret of arsenic.
From the experiments of Margraff and
Pelletier, it seems probable that phosphorus
unites both with arsenic and its oxide. By
distilling a mixture of equal parts of arsenic
and phosphorus in a carefully regulated heat,
Pelletier obtained a residuum of a black shin-
COBALT. 209
ing substance, containing a good proportion
of phosphorus. The same was obtained in
the humid way, by keeping phosphorus in fu*
sion on arsenic under water for some time*
The phosphuretted oxide may be obtained by
distilling phosphorus and the white oxide of
arsenic together* the phosphuretted oxide
sublimes mixed with arsenic and phosphorus
in a separate state. It is of a red colour.
The proportions in neither case were ascer*
tained. It is probable that the compounds
are of the most simple kind, or one atom to
one; in that case we shall have 21 arsenic
and 9i- phosphorus, or 100 arsenic and 44
phosphorus for phosphuret of arsenic; and
28 oxide and 9^ phosphorus, or 100 oxide
and 33 phosphorus for phosphuretted oxide. ]
No precipitation is occasioned by phosphu*
retted hydrogen water in solutions of arsenic.
2S. Phosphuret of cobalt*
f ■
Cobalt unites with phosphorus in the direct
way as well as by being heated with phospho-
ric glass. The colour of the compound is a
blueish white; it is brittle and crystalline in
the fracture. The metal acquires 7 per cent. ;
VOL. II. Dd
210 JPHOSPHURETS.
this is below the theoretic quantity, which is
25 per cent, if the atom of cobalt be 37.
Solutions of cobalt give no precipitate by
phosphuretted hydrogen water.
24. Phosphuret of manganese.
This compound may be formed like the
preceding ones. It is of a white colour,
brittle and of a granular texture. It is not
liable to be altered by the air like the pure
metal. The proportions of the compound
Pelletier did not determine. Reasoning from
theory, it should consist of 25 metal and 9^-
phosphorus; or 100 metal and 37 phos-
phorus.
The salts and oxide of manganese are not
sensibly affected by phosphuretted hydrogen
water.
The combinations of the remaining metals
with phosphorus can scarcely be said to have
been investigated.
CARBURETS. 211
SECTION 16.
CARBURETS.
On the supposition that metals combine
with charcoal, the appropriate names for the
compounds would be carburets of the respec-
tive metals. This combination, if it exist at
all, seems very rare, that with iron being
the only one generally acknowledged. No
combinations of carbone with the earths and
alkalies, have, as far as I know, been no-
ticed ; and those with the elements ox gen,
hydrogen, sulphur and phosphorus have been
described in the former volume. Since that
was printed an ingenious experimental essay
on the " Sulphur et of carbon or alcohol of
sulphur," has been published by Berzelius
and Dr. Marcet. Some account of this com-
pound, under the name carburetted sulphur,
has been given (vol, I. page 462) ; but the
additional information is of sufficient impor-
tance to require notice here. The pure li-
quid is of sp. gr. 1.272 ; and the elasticity of
its vapour at 66° is equal to 10.76 inches*
It burns with a blue flame and sulphureous
212 CARBURETS.
odour, without sensibly depositing water on
cold glass exposed to the fumes. It has an
acrid, pungent taste, and a nauseous smell,
differing from sulphuretted hydrogen. By
various experiments it was found to consist
of sulphur and carbone in the ratio of 85 to
15 nearly ; that is, 2 atoms of sulphur to 1 of
carbone. From other experiments it did not
appear to contain any hydrogen.
From some experiments il made in June
1818, on the combustion of the vapour of
carburet of sulphur in oxygen gas, I was led
to suspect at leasts that an atom of hydrogen
attaches to the two of sulphur and one of
carbone in its constitution. But not having
an opportunity to pursue the subject, I mere*
ly make the observation for future experience
to determine upon the question.
1. Carburets of iron.
There are three distinct substances which
are now commonly believed to be constituted
of carbone and iron, known by the names of
Plumbago, or black lead, Cast Iron and SteeU
Plumbago is a natural production, found
in greatest perfection in the Borrowdale
tnine, near Keswick, Cumberland. It is
CAST IRON. 213
chiefly used in making pencils.- — It seems to
be constituted of carbone and iron by the
concurrent experience of all who have exa-
mined it : but the proportions are not uni-
form, some having found 10 and others only
5 per cent, of iron in it. From this circum-
stance it would seem doubtful whether iron
is an essential element. As carbone is known
to be exhibited in various forms of aggrega-
tion, it is not improbable that plumbago may
be one of those forms ; it is evidently not a
mere mixture of common charcoal and iron,
or its oxide.
Cast iron or crude iron is the metal when
first extracted from the ore; it usually con-
tains carbone, oxygen, phosphorus and silica,
in small proportions, with perhaps other
earths occasionally. It cannot be considered
as having these elements united in definite
proportions; for they vary much, and pro-
bably give to crude iron its several modifica-
tions. Cast iron contains about 80 per cent,
of its weight of iron in a state capable of
solution in dilute sulphuric acid, and yield-
ing a corresponding quantity of hydrogen
gas. The residue, in a specimen 1 examined,
was nearly as magnetic as iron itself. When
treated with boiling muriatic acid, the inso-<
luble part was reduced to 2| per cent, upon
214 CARBURETS.
the original weight of the iron, and some
hydrogen gas given out. It was then about
as magnetic as the common black oxide of
iron ; when heated it assumed a glowing red
and lost nearly \ grain ; it was still magnetic,
and boiling muriatic acid extracted more
iron from it.
The hydrogen gas from dilute sulphuric
acid and cast iron contains no carbonic acid
in my experience ; neither does it yield any
when exploded with pure oxygen gas,
The small residuum after treating cast
iron with acids was found by Bergman and
others to resemble plumbago, being consti-
tuted chiefly of carbone and iron.
From the above it would seem that cast
iron consists chiefly of pure iron, with the
addition of very small proportions of oxygen
and carbone ; the oxygen may be about 1 per
cent, and the carbone about 2. These pro-
portions, though sufficient to modify the pro-
perties of iron to a certain extent, can
scarcely be considered as constituting cast
iron a homogeneous mass.
Steel. This most important modification
of iron has engaged the attention of many
chemists and metallurgists. It may be pro-
cured, but not equally pure, by different me-
thods. One is to keep the cast iron for a
StEEl* 215
considerable time in fusion and in a very
high degree of heat; whilst its surface is
covered with melted scoriae, so as to preclude
the contact of the atmosphere with the iron.
This, it is conceived, gives time for the car-
bone and oxygen to combine and escape in
the form of carbonic acid* This steel is of
inferior purity*
Steel of cementation is made by stratify-
ing bars of pure iron with charcoal powder
in large earthen crucibles, carefully closed
up with clay. These are exposed to a high
degree of heat in a furnace for 8 or 10 days.
This is called blistered steel, from the ap-
pearance of blisters on its surface.
Cast steel is made from blistered steel by
breaking the bars and putting them into a
large crucible with pounded glass and char-
coal. The crucible is closed with a lid of the
same ware and placed in an air furnace.
When the fusion is complete the metal is
cast into ingots. This is the most valuable
and probably the purest steel.
When steel is heated red and plunged into
cold water, it is hardened; that is, it be-
comes much harder than iron or than steel
without this operation. Hardened steel is
brittle, and cannot be extended by the ham-
mer or corroded by a file till it is again sof-
216 CARBURETS,
tened by being heated and then gradually
cooled.
One of the most remarkable properties of
hardened steel is that of being tempered, as
it is called ; by which it is adapted to the
different purposes of the manufacturing art-
ists. -Tempering consists in heating the har-
dened steel till it acquires a straw colour for
edge tools, a blue colour for watch springs,
and elastic articles in general ; &c. &c.
Hardened steel is qualified to acquire mag-
netism, and to retain it so as to become a
permanent magnet. This power of retain-
ing magnetism distinguishes steel from pure
iron.
From the above account of steel, it is evi-
dent there is an essential difference between
it and pure iron. That difference consists,
according to the common opinion, in steel
being a carburet of iron, or carbone and iron
united. The fact of the union of carbone
and iron in the formation of steel does not
seem to me satisfactory proved. Mr, Collier
asserts that iron gains about ^i-^-th of its
weight by being converted into steel,* But
Mr. Mushet found that though steel gains
weight upon the iron when copiously imbed-
* Manchester Memoirs, Vol. v, page 120* .
STEEL, 217
ded in charcoal, yet it loses weight if the
charcoal is only ^ or T-J-5- °f tne weight of
the iron,* The same ingenious gentleman
seems to estimate the carbone in cast steel,
from synthetic experiments, to be T4-^th of
its weight.
From analytic experiments, however, there
does not appear reason to believe that steel
contains so much, if any charcoal. Pure
steel dissolved in dilute sulphuric acid gives
hydrogen gas containing" no carbonic acid
nor oxide, neither is there any appreciable
residuum of any kind in general.
On considering all the circumstances, I
am inclined to believe, that the properties
which distinguish steel from iron are rather
owing to a peculiar crystallization or ar-
rangement of the ultimate particles of iron,
than to their combination with carbone or
anv other substance. In all cases where
at
steel is formed, the mass is brought into a
liquid form, or nearly approaching to it, a
circumstance which allows the particles to
be subject to the law of crystallization. We
see that great change is made in steel by the
mere tempering of it, which cannot be as*
cribed to the loss or gain of any substance,
* Philos. Mag. Vol. xiii.
vol. ii. s e
218 METALLIC ALLOYS.
but to some modification of the internal ar-
rangement of its particles. Why then may
not its differences from iron be ascribed to
the same cause ? It is allowed that steel, by
being repeatedly heated and hammered, be-
comes iron : that is, it should seem, the
change of figure disturbs the regular ar-
rangement of the particles. And it may be
further observed, in corroboration of the opi-
nion that cast iron is capable of being made
permanently magnetic, from its having been
in fusion more probably than from its near
approximation to steel in its component
parts. The most powerful artificial magnets,
after being forged of steel, are said to un-
dergo the operation of steelifying again, be-
fore they are hardened finally to receive the
magnetic virtue.
SECTION 17.
METALLIC ALLOYS.
When two or more metals of different
specific gravities are melted together and in-
timately mixed, they frequently enter into
chemical union and form a new compound,
called an alloy of the metals. These alloys
METALLIC ALLOYS, 219
often possess important properties which
their constituents singly do not, and hence
become valuable acquisitions to the arts.
The metals thus combined may be fused to-
gether in any proportion ; but if one of them
greatly exceed the other in specific gravity,
their intimate union is sometimes rendered
difficult and even impracticable, partly from
the weak affinity and partly from the gravi-
tating principle causing the metal of least
specific gravity to arise to the surface.
Notwithstanding this union of metals in
seemingly indefinite proportions, there are
only a few proportions in which the alloys
possess peculiar excellences so as to entitle
them to the attention of artists. These pro-
portions have in many instances been disco-
vered by experience ; and it only remains
for theory to point out the reason for such
proportions, and to suggest other propor-
tions which may bid fair to possess desirable
qualities, and thereby diminish the unsuc-
cessful attempts for improvement in these
combinations.
That the metals thus alloyed constitute
true chemical compounds and not merely
mechanical mixtures, may be inferred from
the change made in their primary qualities ;
such as
220 METALLIC ALLOYS.
1. Tenacity, hardness, &c. Some alloys
are much superior to their ingredients in
tenacity and hardness, whilst others affect a
kind of medium between them. This last is
often the case too in regard to ductility and
malleability.
2. Fusibility \ Several alloys fuse at tem-
peratures intermediate between the fusing
temperatures of their ingredients, but mostly
lower than the mean ; there are others which
fuse below the temperature of the lowest,
and few if any require a temperature above
the mean for their fusion.
3. Colour. In many cases the colour of
alloys is such as would be produced by the
mixture of the colours of the metals; but in
others, remarkably different ; for instance,
the alloys of copper and zinc, — forming the
various kinds of brass.
4. Specific gravity . This is not always what
might be inferred from a mixture of the two
ingredients. Sometimes it is greater and
other times less ; but this is not a decisive
mark of chemical union, as the same metal
varies in specific gravity, by hammering,
rolling, tempering, &c. very considerably.
Besides, it is more than probable that the
differences said to have been observed, have
in some instances arisen from inaccurate expe-
METALLIC ALLOYS. 221
riments ; as it is a delicate operation to find
the specific gravity of small pieces of metal
with sufficient precision for comparisons of
this kind.
Many of the simple metals, when fused
and exposed to the air for some time, with-
out a covering of charcoal, or some similar
principle, acquire less or more of oxygen,
and retain it even in a fluid state, as is proved
from Mr. Lucas's interesting communication
in the 3d VoL of the Manchester Society's
Memoirs (new series). Hence by frequent
fusions of the same metal its quality becomes
impaired in regard to tenuity and other pro-
perties,
This is more eminently the case with re-
gard to alloys. Thus, zinc at the tempera-
ture in which brass melts is combustible ; and
hence a portion of it escapes by combustion.
Hence the proportions of brass are changed
less or more at each fusion, unless fresh zinc
be added. The same observation applies to
alloys of copper and tin with regard to the
tin. The mixtures of lead, tin, bismuth and
other soft and easily fused metals, are still
more remarkable in this respect. They
should be fused under a cover of oil or tal-
low in order to keep them of the same pro-
portions ; otherwise, some of them, parti-
222 METALLIC ALL.OYS.
cularly the tin, is liable to great oxidation,
and no two successive fusions will present
the same alloy. Hence in some degree the
use of fluxes in metallurgy which serve to
cover the surface of the metals and prevent
oxidation from the atmosphere.
When an alloy is made, it seldom happens
that the metal is perfect and compact the
first fusion ; it is more or less porous, espe-
cially when the two metals fuse at very dif-
ferent temperatures. By a second fusion,
which usually takes place at a much lower
temperature than that requisite for the first,
the metal becomes compact and free from
pores. This is particularly the case with
speculum metal ; and I have little doubt it is
so with regard to many other alloys.
Alloys* of Gold with other Metals.
Gold unites with many of the metals by
heat, and forms various alloys, on which it
may be proper to make a few remarks.
1, Gold with platina. Platina in a small
proportion changes the colour of gold to-
wards white. 1 part to 20 gold makes it
much paler. 1 to 11 gives it the colour of
GOLD WITH SILVER, &C. 223
tarnished silver. 1 part with 4 of gold has
much the appearance of platina. The co-
lour of gold does not predominate till it be-
comes -§- of the alloy. The alloy of 1 platina
and 11 gold is very ductile, and elastic when
hammered. Lewis, Klaproth. Vauquelin.
2. Gold with silver. These two metals
may be combined in almost any proportion
by fusion and proper treatment. Homberg
found that when equal parts of gold and
silver are kept in fusion for a quarter of an
hour and then cooled, there were two masses,
the uppermost pure silver, the undermost an
alloy of 5 parts gold and 1 silver. I part
silver to 20 gold produces a sensible white-
ness in the alloy. 2 parts gold and 1 of
silver are stated to form the alloy of greatest
hardness ; this will consist of 3 atoms of gold
to 1 of silver.
3. Gold with mercury. See amalgams.
4. Gold with copper. Gold and copper
form an alloy by fusion together. 11 parts
gold and 1 copper form the alloy used for
gold coin. The copper heightens the colour
of the gold, and makes it harder and less
liable to wear. The current gold coin, how-
ever, usually contains both silver and copper,
but the weight of both does not much ex-
ceed one twelfth of the whole. According
224 METALLIC ALLOYS.
to Muschenbroeck the maximum of hardness
is when 7 parts of gold and 1 part of copper
are united. This corresponds nearly to 6
atoms of gold and 1 of copper, the atom
of gold being estimated at 66 and that of
copper at 56.
Other alloys of gold besides the above
standard is that for watch cases, which must
contain at least J pure gold. Watch chains,
and trinkets, are usually made of inferior al-
loy, called jewellers gold, which is under no
controul. It rarely contains less than 30 per
cent, of pure gold.
5. Gold with iron. Gold and iron may be
united by fusion in various proportions. 11
parts gold and 1 iron form a ductile alloy
which may be rolled and stamped into coin.
Its specific gravity is 16.885. The colour is
a pale yellowish gray approaching to white.
The alloy is harder than gold. When the
iron is three or four times the weight of gold,
the alloy has the colour of silver. This last
compound is constituted of 1 atom of gold
and 8 of iron nearly, Lewis. Hatchett.
6. Gold with nickel. Mr. Hatchett fused
11 parts gold and 1 nickel together, and ob-
tained a brittle alloy of the colour of fine
brass.
7. Gold with tin. Gold combines with
GOLD WITH LEAD, ZINC, &C. 225
tin and forms a brittle alloy. 10 parts gold
and 1 tin form a pale alloy and less ductile
than gold. One fiftieth of tin does not ma-
terially injure the ductility. Heat, up to a
visible red, does not impair the alloy ; but
beyond that the tin fuses and the alloy falls
to pieces. Hatcheit.
8. Gold with lead. The effect of uniting'
even a very small proportion of lead to gold
is remarkable. When the alloy contains
-.j-^Vtf part of lead, it is brittle like glass.
The vapour of fused lead in close vessels is
sufficient to injure gold. ibid.
9. Gold and zinc. These two metals com-
bine in almost any proportion. When 11
parts gold and 1 zinc are alloyed, the com-
pound is of a pale greenish yellow like brass,
and very brittle. Equal parts of these me-
tals form a very hard, white alloy, suscepti-
ble of a fine polish, ibid. Sc Hellot.
10. Gold and bismuth. Gold unites with
bismuth, but the colour is injured and the
ductility of the alloy destroyed by a very
small portion of the latter metal, the same
as with lead. ibid.
11. Gold and antimony. These metals
combine and produce a brittle alloy, much
of the same kind as those with bismuth and
lead. ibid.
VOL, II. f f
226 METALLIC ALLOYS.
12. Gold and arsenic. There seems a con-
siderable affinity between gold and arsenic,
but the volatility of arsenic in the fusing tem-
perature of gold renders it difficult to bring
them into contact. A very small proportion
of arsenic makes the alloy brittle, and this
property increases with the arsenic. Hatchett.
13. Gold with cobalt. These unite and
form a brittle alloy, even when the cobalt
only makes -^ of the compound, ibid.
14. Gold and manganese. Gold and man-
ganese may be united, and the alloy is very
hard and less fusible than gold. One alloy
was found to consist of 7 or 8 parts of gold
and 1 of manganese, ibid.
Alloys of Platina with other Metals*
1, Platina mid silver. It does not appear
very clear that these two metals combine by
fusion ; at least if they do, the difference in
their specific gravities is sufficient to over-
come their affinity.
2, Platina and mercury. See amalgams.
3, Platina and copper. These two metals
unite with difficulty by a strong heat and
form a malleable alloy. This alloy has been
preferred for specula for telescopes, as it is
PLATINA AND TIN, LEAD, ZINC, &C. 227
hard, polishes well, and is not liable to tar-
nish. Lewis.
4. Platina and iron. Platina and soft or
pure iron do not seem to be easily combined
by heat, by reason of the infusibility of iron.
But it combines with cast iron and steel by
heat. The alloy is very hard, and in some
degree ductile when the iron forms J of tbe
alloy, ibid.
5. Platina and tin. Equal parts of pla-
tina and tin unite by fusion, and form a dark
coloured brittle alloy. But when the platina
falls short £ of the alloy, the ductility and
whiteness proportionally increase, ibid.
6. Platina and lead. These two metals
may be combined in various proportions by
heat ; but the compounds are not stable, part
of the platina falling* down, when the alloy is
subsequently melted* ibid.
7. Platina and zinc. Platina may be com-
bined with zinc, by being exposed to the
fumes of the metal as reduced from its ore.
Three parts of platina become four of alloy.
It is hard, brittle, of a blueish white colour,,
and easily fusible, ibid.
8. Platina and bismuth. Platina, and bis-
muth combine readily in a high temperature
in almost any proportions. The alloys are
brittle, ibid.
228 METALLIC ALLOYS.
9. Platina and antimony. Platina easily
combines with antimony by heat. The alloy
is brittle, ibid.
10. Piatrna and arsenic. When white
oxide of arsenic is projected upon strongly
heated platina, an imperfect union takes place
with a partial fusion of the mass 3 it is brittle,
of h greyish colour and a loose granulated
texture. Lewis,
Alloys of Silver with other Metals,
1. Silver with mercury. See amalgams.
2. Silver with copper. Silver and copper
are easily alloyed in any proportion by fu-
sion. The compound is harder than silver,
and retains its white colour when the copper
is half of the alloy or more.— The silver coin
is a compound of 12- silver and 1 copper,
which nearly corresponds to 8 atoms of sil-
ver and 1 of copper. The hardest alloy is
said to be when 5 silver unite to 1 copper ;
that is, 8 atoms of silver and 1 of copper,
3. Silver with iron. The alloys of silver
and iron have not been very minutely exa-
mined. The two metals are said to unite by
fusion, but the iron still retains its magnet-
ism. The alloy is of a white colour, hard
SILVER AND ZINC, BISMUTH, <ScC. 229
and ductile. When kept in fusion for some
time the two metals separate, but not entire-
ly. These circumstances shew the affinity
between silver and iron to be weak.
4. Silver with tin. Silver and tin form a
hard brittle alloy, which is of little if any
use. The modifications arising from various
proportions have not been particularly inves-
tigated.
5. Silver and lead. Silver and lead unite
in any proportion and form a brittle alloy
of a lead colour. The union is not very in-
timate; for when urged by heat the lead
parts from the silver, as in the process of
cupellation.
6. Silver and zinc. These two unite and
form a brittle alloy of a blueish white colour.
The proportions have not been particularly
noticed.
7. Silver and bismuth. Silver and bismuth
readily unite by heat. The alloy is brittle
and its colour inclines to that of bismuth.
8. Silver and antimony. These metals unite
by fusion and form a brittle alloy, which
does not seem possessed of any remarkable
properties.
9. Silver and arsenic. These two metals
unite according to Bergman, the fused silver
taking up ^ of its weight of arsenic; the
230 METAIATC ALLOYS.
alloy corresponds nearly to 3 atoms silver and
1 arsenic. It is brittle and of a yellowish
colour.
Alloys of Mercury arid other Metals:
Amalgams.
The alloys of Mercury with the various
metals have been commonly denominated
amalgams,
1. Mercury and gold. Gold amalgamates
pretty easily with mercury and forms an
alloy much used in gilding metals. For this
purpose six parts of mercury may be heated
nearly to the ebullition of the liquid, and one
part of pure gold in thin plates may be gra-
dually added. In a few minutes the whole
becomes one fluid mass of a yellowish white
colour. It is constituted of 1 atom of gold
and 2 of mercury. By squeezing it through
leather one half of the mercury is separated
nearly pure, and the other remains com-
bined with the gold, and forms a soft white
mass, consisting of 1 part gold and 2f mer-
cury nearly, which is the alloy of I atom to
1, and may be subsequently used for gilding.
A ready way of making this amalgam I find
is to put 3 parts of gold, precipitated by
AMALGAMS, 231
green sulphate of iron, to 8| or 9 parts of mer-
cury ; by a few minutes trituration the whole
becomes a fine crystalline amalgam. — When
this amalgam of gold is exposed to a heat
just below red, the mercury sublimes and
leaves the gold ; hence its use in gilding.
2. Mercury and platina. These two me-
tals may be combined, but not very easily,
as little affinity seems to exist betwixt them.
This is manifest from the circumstance that
platina wire may be long immersed in mer-
cury without any sensible effect. An union
may be produced by immersing thin platina
foil into boiling mercury for some time ; also
by triturating the animonio-muriate of pla-
tina with mercury and exposing it to a due
heat. The proportions have not been deter-
mined.
3. Mercury and silver. Silver and mer-
cury have a considerable affinity and are
easily combined by putting lamina of silver
into heated mercury and agitating the mix-
ture. When 1 part silver and 2 mercury are
mixed as above, a fluid mass is obtained which
being heated to the temperatwre of boiling
mercury, a little mercury evaporates and the
remainder crystallizes into a soft white mass,
which in time grows hard and brittle. A
232 METALLIC ALLOYS.
higher heat than boiling mercury expels the
mercury. Hence this amalgam may be used
for giving a thin coating of silver to the sur-
face of metals, like that of gold. The com-
pound is evidently one atom of silver (90)
with one of mercury (167).
« 4. Mercury and copper. I have made se-
veral unsuccessful attempts to combine mer-
cury and copper.
When a plate of copper is kept immersed
in mercury for some time, the mercury ad-
heres to its surface in a small degree and is
not easily rubbed off; the plate is rendered
brittle by it and the fracture has a brilliant
mercurial appearance; but a low red heat
expels the mercury and the copper resumes
its colour and tenacity, with scarcely any
loss of weight, being only about 5§ per cent*
in two or three trials.
Recently precipitated copper in powder,
dried and triturated with mercury, produced
no union. Neither did Dutch-leaf (which is
copper with a very little zinc) unite with
mercury by trituration. Mercury precipita-
ted from deutonitrate by a plate of copper
gave pure running liquid. The plate of
copper appeared as if it had been immersed
in mercury, was brittle with a shining frac-
AMALGAMS. 233
ture, but recovered its colour and texture by
heat, and lost scarcely any weight.
The method recommended by Boyle was
tried : 2f parts of crystallized verdigris, 2
parts of mercury and 1 of common salt, were
triturated together till the mercury disap-
peared, the powder was then digested awhile
with vinegar over a fire and frequently stir-
red. The mass was then put on a filter and
dried. It contained a little fluid mercury,
but was chiefly composed of acetate of cop-
per and oxide or muriate of mercury. The
liquid contained acetate of copper and mu-
riate of soda.
From the above it is manifest that mercury
has some chemical action upon copper ; but
it has not yet been found, I apprehend, that
the two metals unite so as to form a proper
amalgam.
5. Mercury and iron. These two metals
have little if any affinity for each other. I
do not know that any chemical combination
of them has ever been formed.
6. Mercury and tin. These two metals
readily combine, especially if assisted by
heat, I heated 52 parts of tin and 167 of
mercury together, that is, 1 atom of each^
till they united in a fluid mass. The amal-
gam crystallized in about 180°. By hard
234 METALLIC ALLOYS.
pressure in the hand nearly 50 parts of fluid
mercury were separated from the amalgam
when cool, containing in appearance very
little tin. After this an amalgam was formed
of 104 parts of tin and 167 mercury (2 atoms
tin to 1 mercury); this congealed about 230°,
and remained a hard, dry, crystalline sub-
stance, agreeing in appearance with that
which adheres to mirrors. For the purpose of
silvering mirrors however much more mercury
is employed than is indicated by the above pro-
portion; but after the glass is slid upon the
tinfoil previously covered with mercury, a
great pressure is applied, which expels the
superfluous mercury nearly in a state of
purity.
7. Mercury and lead. To 90 parts of lead
1 put 167 of mercury (I atom of each) ; they
united in a moderate heat and crystallized in
about 180°. In a few days the mercury
partly separated from the amalgam, and 56
parts were squeezed out, the whole was then
put together with 90 parts more of lead (now
2 atoms lead to 1 mercury), and fused toge-
ther; the amalgam crystallized in about
200°, and remained in a solid uniform mass.
8. Mercury and zinc. When 29 parts zinc
and 167 mercury (1 atom to 1) are heated
together, they combine and form an amalgam
AMALGAMS. 235
which crystallizes about 200° . A little of the
mercury may be squeezed out when cold. By
putting1 29 parts more of zinc (2 atoms to 1)
we obtain an amalgam which fuses consider-
ably above 200°, and when cooled becomes
a permanent hard crystalline mass.
9. Mercury and bismuth. When 62 parts
bismuth are fused with 167 mercury (1 atom
to 1), the compound remains fluid at com-
mon temperature, but crystallizes partially by
standing; about 4. of the weight may be pour-
ed off like fluid mercury. If we put 62 bis-
muth more to the whole (so as to be 2 atoms
to 1), the fluid amalgam crystallizes about 150
or 180° : the mass is soft however and by pres-
sure one may squeeze out about 20 per cent,
of a fluid amalgam. If we put 62 more bis-
muth (so as to be 3 atoms to 1), then the com-
pound crystallizes between 200 and 300° into
a darkish coloured granular soft mass which
continues without any change. Higher than
this of bismuth I have not examined,
10. Mercury and antimony. Antimony is
said to form a feeble union with mercury,
which is soon loosened by time. I made se-
veral unsuccessful trials to combine these two
metals, which it seems unnecessary to detail,
as the compound when formed is no ways
interesting.
236 METALLIC ALLOYS.
11. Mercury and arsenic. On the autho-
rity of Lewis an amalgam of mercury and
arsenic may be made by keeping them over
the fire for some time and constantly agitat-
ing the mixture. It is grey-coloured, and
composed of 5 parts of mercury and 1 of
arsenic.
Most of the other metals are incapable,
as far as is known, of combination with mer-
cury, excepting potassium and sodium con-
sidered as metals, which combine with mer-
cury ; but these alloys are of little interest,
and the proportions have not been particu-
larly investigated.
Triple, quadruple, fyc. Amalgams.
Besides those amalgams which are formed
of mercury and each single metal, there are
others formed of mercury and alloys of two
or more metals, which in some instances pos-
sess properties differing essentially from mere
mixtures.
1. Mercury with bismuth and lead. When
the amalgam formed of 2 atoms bismuth and
1 of mercury is mixed with that formed by
1 atom of lead and 1 of mercury, in such
AMALGAMS. 237
proportion that the mercury is the same in
both, the two powders, though dry and crys-
talline at first, soon become a permanently
fluid amalgam by trituration. The liquid in
running along drays a tail after it, and is
disposed to separate into portions less and
more fluid, but the most fluid part is much
inferior to pure mercury in this respect.
Specific gravity of the amalgam, 11.
2. Mercury with fusible metal composed of
1 bismuth, 5 lead and 3 tin. A mixture
of 4 parts fusible metal with 5 parts mercury
compose the most fusible amalgam with a
minimum of mercury that I have found. It is
formed of 2 atoms bismuth, 1 lead, 1 tin and
2 mercury. Its specific gravity is 12.
3. Mercury* zinc and tin. This amalgam is
found the most effectual for the excitation of
electric machines. Mr. Cuthbertson recom-
mends 1 part zinc, 1 tin and 2 of mercury
for the plate machine amalgam. But for a
cylinder the best amalgam I have made con-
tains more than twice the above portion of
mercury. I form an alloy of 58 parts zinc
and 52 tin, (2 atoms to 1). To this alloy I
add 250 mercury, and fuse the mixture;
the liquid mass crystallizes about 222° into a
white, moderately hard amalgam. This is
pulverized in a mortar and mixed up with T*T
238 METALLIC ALLOYS.
of its weight of hog's lard. A jsmall portion
then is spread upon a piece of leather and
applied to the machine when in action. It
is probable however that a harder and less
unctuous amalgam may be better adapted to
the plate machine. This amalgam of mine
consists of 4 atoms of zinc, 2 of tin and 3 of
mercury.
I have tried the amalgams of zinc and tin
separately and find that they answer for elec-
tric excitation as well as when combined.
They ought to be formed of 2 atoms zinc
and 1 of mercury (58 parts to 167), and of
2 atoms tin and 1 of mercury (104 parts to
167). If we choose to combine them, we
have only to take 2 parts of the zinc
amalgam and 1 of the tin amalgam and tri-
turate them together.
Bismuth amalgam is not good for electric
excitation; lead amalgam is better; but
they are much inferior to those of tin and
zinc.
Alloys of Copper with other Metals.
1. Copper and iron. These two metals may
be united with difficulty by heat; but the
compound possesses no useful property.
2. Copper and nickel. A white, hard,
COPPER AND TIN. 239
brittle alloy is said to be formed by combining
these two metals. The alloy is scarcely
known.
3. Copper and tin. The metals of cop-
per and tin, may be fused together and united
in almost any proportion by skilful treat-
ment ; but it is found that only a few of the
proportions constitute alloys possessing pro-
perties eminently valuable to the arts,
The alloys of copper and tin are commonly
called bell-metal; but they receive more par-
ticular names according to the purposes for
for which they are destined, as bronze, spe-
culum-metal, gun-metal, &c. those of them
which are yellow are frequently confounded in
common language with brass, as brass-guns,
&c. Indeed the ancient Greeks and Romans
seem to have been in possession of these two
alloys, under one and the same name. The
x*kkos of the Greeks, being used for cutting-
instruments, must have signified bell-metal,
or the alloy of copper and tin as well as brass,
as indeed is proved by the analysis of them.
The ces of the Romans seems also to have
included the same compound. Ancient cop-
per coins too are usually found to contain
tin.
Tin united to copper in certain proportions
gives a surprising degree of hardness and ten-
240 METALLIC ALLOYS.
acity to the alloy, much superior in these res-
pects to either of the ingredients. In other
proportions it makes the compound highly so-
norous, as in bell-metal properly so called. Tin
also increases the fusibility of the compound
in proportion as it abounds, being itself
fusible at the low temperature of 440°
Fahrenheit.
The principal varieties in the alloys of
copper and tin are enumerated below, be-
ginning with those in which the copper is
most abundant. The atom of copper is taken
at 56 and that of tin at 52 weight, the hard-
ness of these metals is denoted by 7.5 and 6
respectively, by Kirwan,
(a). Gun-metal. The alloy for brass guns
or cannon is made of 100 parts of copper and
11 or 12 of tin. A small portion of iron is
found to improve the metal ; this is best add-
ed in the state of tin-plate, as it more readily
fuses and unites with the metal.* This com-
pound is hard and extremely tenacious, ex-
ceeding in this respect any other alloy of the
two metals. The addition or subtraction, of
* See a very excellent essay on the alloy of copper and
tin by M. Dussaussoy, in the Anhales de Chimie & Phy-
sique. 5—113.
COPPER AND TIN, 241
1 or 2 parts of tin materially impairs the
tenacity of the alloy. It is constituted of
8 atoms of copper and 1 of tin.
(b)% Alloy for edge tools, printers* cylin-
ders, fyc. The best proportion for this com-
pound seems to be 100 parts copper and 15
or 16 tin. When hammered and tempered
duly it is fit for making* edge tools not infe-
rior to some kinds of steel. It is a compound
of greater density than the preceding,
though containing more tin ; the grain is
fine and the metal free from blisters and suited
for turning in the lathe. It seems to he the
best alloy of the kind for printers* cylinders;
but an analysis which I lately made of ome
turnings from one of these cylinders gave me
much less tin than the above proportion.
The alloy (b) is constituted of 6 atoms of cop-
per and 1 of tin
(c). Alloy for the Chinese gong, cymbals, $c.
An alloy formed of 100 parts copper and 23
tin, appears from Dussaussoy's experiments
to form the compound of minimum density.
It is used for making cymbals; and nearly
accords with the composition of the Chinese
gong. It is formed of 4 atoms of copper
and 1 of tin. The Chinese gong analysed
by Klaproth was composed of 100 copper and
VOX,. II. H k
242 METALLIC ALLOYS.
28.2 tin ; that by Dr. Thomson of 100 copper
and 23.4 tin.
(d). Common bell-metal used/or casting bells.
This alloy is commonly made of 3 parts cop-
per and 1 of tin ; but to be in due proportion
for 3 atoms of copper and 1 of tin, it should
be formed of 100 copper and 31 tin. It is
hard, of a white colour, less malleable than
the preceding alloys, and more sonorous*
A specimen I analysed consisted of 100 cop-
per and 36 tin. The exact proportion of
100 copper and 31 tin is not essential to
produce a sonorous alloy.
(e). Speculum metal. This compound has
been investigated with great care by opti-
cians. According to Mr. Mudge the best
proportion is 32 parts copper to 14.5 tin, but
Mr. Edwards finds 15 parts tin, 1 brass, 1
silver and I arsenic. The slightest variation
in the proportions of copper and tin impairs
the metal. The alloy is white, hard and
close grained ; it takes a beautiful polish.
The use of the minute portions of zinc, sil-
ver and arsenic is perhaps to correct the co-
lour of the alloy ; though it seems in several
alloys that very minute portions of metals
apparently foreign to the alloy, improve the
density and texture of the metal. It is re-
k markable with what precision this alloy
COPPER AND TIN. 243
accords with the atomic combinations of 2
copper with 1 tin. By calculation 32 copper
would require 14.8 tin. Mr. Mudge finds
32 copper to 14| tin, and observes that ;f f
a part more of tin be added the metal is too
hard. Mr. Edwards indeed says 32 copper
and 15 tin ; but then he adds 1 part brass,
which containing f of a part of copper, it
reduces his proportion to 32 copper and
14.7 tin, almost exactly that required by the
theory. When 32 copper and 13| tin are
combined, Mr. Mudge asserts the metal is
too soft.*
(f). Copper and tin, equal parts. This
alloy is of blueish white colour, and of no
particular use that I am acquainted with.
It consists of the union of 1 atom of copper
with 1 of tin.
The other alloys of copper with a higher
proportion of tin appear to be unintere ting,
and have not been objects of much attention.
Not having an opportunity of forming these
alloys synthetically, I contented myself with
the analysis of several of them.
* This author obtained the Royal Society's gold medal
for his essay on the composition, &c. of specula for tele*
scopes. Philos. Transact 1787.
244 METAXX.IC AIXOYS.
The mode of, anialysis I adopted, with com-
pounds of copper and tin, is simple and easy.
The alloy is treated with nitric acid, which
dissolves the copper, and . on being dilute4 ,
with water throws down tjie tin in the state
, ■■ .- » < •
of deutoxide. This last is collected on a filtre,
dried, and heated to a 1owa red ; then 44 of
this is allowed for the tin (the other 7 parts
being oxygen ) ; and the rest of the alloy may
be considered as copper. But i( thought
proper the copper may ber thrown down by
immersing1 a plate of lead in the solution,
which succeeds better than a plate of iron in
nitric solutions of copper.
4. Copper and lead. Copper s unites with,
boiling lead and forms a grey brittle , alloy
of granular texture. This alloy being heated
above the melting point of lead, causes the
last metal to run off, leaving the copper
nearly pure. The alloy is scarcely of any
use.
5. Copper and zinc. Copper and zinc
combined form brass, one of the most use-
ful of all alloys. Though this is a general
name for such combinations, yet several of
the proportions form compounds to which
peculiar names are given, some of which will
be noticed below.
It may be proper to remark that copper is
BRASS. 245
estimated by Mr. Kirwan at 7|° in hardness,
whilst zinc is 6f . The former metal is highly
tenacious and malleable; the latter is brittle
and malleable only in a small degree. Ac-
cording to Lewis^ a very small proportion of
zinc dilutes the colour of copper and renders
it pale ; when the copper has imbibed TV $C
its weight, the colour inclines to yellow..
The yellowness increases with the zinc till
the weight of that metal in the alloy equals
the copper. Beyond this point if the zinc
be increased the alloy becomes paler and
paler and at last white, like zinc.
The tenacity of brass is greater than that
of either copper or zinc according to Mus-
chenbroek. His experiments give brass
nearly twice as strong as copper, and 18 times
as strong as zinc. It seems to me most pro-
bable that the tenacity of brass increases
with the increase of zinc in the alloy to a cer-
tain proportion, when it becomes a maximum,
and thence diminishes with the further in-
crease of zinc, but experiments are yet want-
ing, I presume, to ascertain what proportion
of the two metals must be taken to form the
alloy of greatest tenacity. The same obser-
vation may be made as to the maximum hard-
ness ; it is not improbable that the two maxi-
ma may be found in different kinds of brass.
246 METALLIC ALLOYS.
The point of temperature at which copper
fuses is stated to be 27° of Wedgwood's
thermometer, whilst that of zinc is much
lower, namely, 680° of Fahrenheit. Com-
mon brass is stated to melt at 21° of Wedg-
wood. It is very probable that all kinds of
brass melt at temperatures intermediate be-
tween those of copper and zinc; and that the
more of zinc the lower will be the fusing
temperature ; but there have not been direct
experiments to ascertain the degrees, as far
as I know.
In enumerating the different proportions
of such alloys as have come under my notice
I shall begin with that containing the maxi-
mum of copper, and proceed in gradation to
that with the maximum of zinc.
(a). Brass for the manufacture of plated
goods. This alloy is composed, judging from
one specimen I analysed, of 12 atoms of cop-
per and 1 of zinc ; or of nearly 23 parts of
copper by weight and 1 of zinc. The atom
of copper is here estimated at 56 and that of
zinc at 29, or very nearly \ that of copper*
This alloy had much the same qualities ap-
parently as copper itself, only a little more
yellow.
(b). Dutch gold, gilding metal. This is the
alloy which may be beaten out into thin
BRASS. 247
leaves, after the manner of gold-leaf. I have
not been able to find any proportions for this
compound in books. It seems to have been
kept as a secret by the manufacturers. By
analysis however I find it composed of 6 atoms
of copper and 1 of zinc, or nearly 12 parts
copper and 1 zinc by weight. This alloy is
probably the most malleable of all the kinds of
brass. A leaf containing 12 square inches
weighs about ^ of a grain. The colour, as
is well known, makes a good approach to
that of gold. It is the composition used for
making articles to be gilt, as buttons, &c.
(c). Dipping metal for stamped brass goods.
This is a well known article of Birming-
ham manufacture. It is an alloy both tena-
cious and malleable, as is manifest from the
perfection of the articles. It possesses a
beautiful gold colour. A specimen was com-
posed, by my analysis, of 4 atoms of copper
to 1 of zinc; or of 8 lbs. of copper and 1
of zinc; or of 4 lbs. copper and 3 of com-
mon brass ; but it is varied according to the
colour wanted.
(d). Soft, fine coloured brass. According
to M, Sage, a very fine kind of brass may
be made by mixing oxide of copper, cala-
mine, black-flux and charcoal powder toge-
gether, and fusing the mixture in a crucible
248 METALLIC ALLOYS.
till the blue flame disappears. The brass h
found to weigh 4 more than the copper result-
ing from the weight of oxide. He says when
the copper retains f of zinc the colour is not
so fine; and the excess of zinc will be burn-
ed off by heat, but the zinc cannot be reduced
by burning below ^-; so that this appears to
be a natural limit. Hence this compound,
being formed of 6 parts copper atod 1 of zinc,
must be constituted of 3 atoms of copper and
1 of zinc,
(e). Soft brass preferred for watch move-
ments. There is a kind of brass greatly pre-
ferred by watch-makers On account of its
working well with steel. I have not met
with a specimen ; but Dr. Thomson has ana-
lysed one and found it to consist of 2 atoms
of copper and 1 of zinc;* or 4 parts cop-
per and I of zinc by weight nearly.
(f). Common hard brass. This constitutes
the great bulk of brass, as manufactured ift
the large way. It is made by exposing gra-
nulated copper, calamine, that is, a natite oxide
of zinc, and powdered charcoal itt mixture to
a red heat for some hours, and then increasing
the heat so as to melt the compound of cop-
* An. of Mos. Vol tttt
BRASS. 249
per and zinc, the charcoal having carried
away the oxygen of the calamine. The me-
tal is then cast into ingots or plates as may
be required. This is called brass of ce-
mentation as distinguished from the other
species, which are usually made from this by
fusion with copper or zinc as the case
requires.
It is found that 401 bs. of copper with 60lbs.
of calamine yield 60 lbs. of brass; hence
a great part of the zinc burns away during
the process. The brass thus resulting, con-
sisting of 2 parts of copper and 1 of zinc,
is of course constituted of 1 atom of each
metal united together.
Common brass is malleable, when cold,
like the preceding species ; but probably
does not possess that property in so high a
degree. It seems better adapted for turning
in the lathe than any other kind of brass.
The specific gravity of this brass before it is
hammered or rolled is generally about 8.1
or 8.2 by my experience. When rolled it
receives a great increase of density, amounting
to ,5 according to M. Pussaussoy*, so that
what is 8.2 when cast will be 8.7 when rol-
* An. de Chim. & Physique. 5—233.
Voii. II. I i
250 METALLIC ALLOYS.
led ; or it is condensed nearly ^ of its volume
by the operation of rolling. The same an*
thor finds that brass is hardened very consi-
derably by rolling, but rendered less tena-
cious ; however by being1 heated and con-
sequently softened after rolling, it becomes
stronger than ever, and nearly of an interme-
diate specific gravity between cast and rol-
led brass.
{g). Prince's metal, pinchbeck, &c. This
compound, as far as 1 can learn, is usually
formed by combining equal weights of cop-
per and zinc, or by fusing together 3 parts
of common brass with 1 of zinc. According
to Lewis the yellow colour of brass is a maxi-
mum in this proportion. The alloy is brit-
tle, or at least much less malleable than com-
mon brass. I find tbe composition of spelter
solder, as it is called, or that used for solder-
ing both brass and copper, to be nearly equal
parts of copper and zinc. Hence it appears
that 1 atom of copper unites to 2 of zinc to
form this alloy.
The other alloys of copper and zinc in
which the zinc gradually exceeds the copper,
become gradually paler in colour and more
prince's metal, pinchbeck, &c. 251
brittle. They do not promise to be of much
utility in the arts, and have not therefore
been very particularly investigated by me-
tallurgists.
Besides the binary combinations of cop-
per and zinc and copper and tin, there are
ternary combinations of these metals, namely,
alloys of copper, zinc and tin. For instance,
the metal of which common white buttons
are made. I had occasion to analyse a spe-
cimen of this metal and found it to be con-
stituted of 4 parts copper, 1 of zinc and 1 of
tin ; or 4 atoms of copper, 2 of zinc and 1
of tin.
It will be proper to subjoin the methods
of analysis which I adopted in regard to
brass. Twenty grains, more or less, of the
particular articles were dissolved in nitric
acid, and the metals were precipitated in the
state of sulphurets by hydrosulphnret of
lime. The copper is thrown down in the
state of a black powder, and the zinc in that
of a white powder turning to grey. Great
care was taken to add tlie precipitating liquor
gradually in order that the copper might be
obtained distinctly from the zinc. The whole
252 METAIXIC ALLOYS,
of the copper is thus thrown down before
any of the zinc precipita>t& appears. The
precipitates were collected and dried in a
temperature not exceeding 150°, and then
weighed. In both cases one third of the
weight was allowed for sulphur, and the re-
maining two thirds were estimated to be me-
tal ; which is agreeable to the known con-
stitutions of these sulphurets. Another me-
thod I sometimes practised, which also answers
very well; namely, to throw down the whole
or greatest part of the copper by a plate of
]e,ad# tfyen to, thrc-w dqwn #ie lead by sulphu-
ric acid \ after this the liquor was tested by
hydrosulphuret of lime to precipitate the
copper remaining, if any ; and lastly to throw
down the zinc by hydrosulphuret of lime.
. $. Copper and bisyiuth. TJie alloy, is J^rit-
vjtle. and of a pqle colour,. It is not, much
known.
j j 7,. Copper with antimony. Copper and
antimony unite by fusion and forni a violet
.coloured, brittle alloy.
...... 8. .Copper, and arsenic. These m^e^al s unite
Jby fusion in a clpse crucible, the surface of
the mixture being covered with common salt
to prevent the oxidizement of the. arsenic.
The alloy is white, .and bri^e, and is known
' i- It -J '. ,t ■ • . r ■ I 'I.I ;.: ! I* ' \$i
IRON WITH TIN. 253
by the names of white copper, and white
tombac. < ,
9. Copper and manganese. These may be
united by fusion, and form a red coloured
malleable alloy, according to Bergman.
1 0. Copper and molybdenum . These metals
may be alloyed in various proportions, but the
compounds exhibit nothing peculiarly re-
markable*
Alloys of Iron with other Metals.
1. Iron with tin. These two metals are
alloyed with some difficulty by fusion in a
close crucible. The difficulty seems to arise
frQm the very unequal temperatures at which
the metals individually fuse. Bergman al-
ways found two alloys when the metals were
fused together ; the one composed of 21 parts
tin and I qf iron, that is> 10 atoms of tin to
1 of iron ; and the other of 2 parts iron, and
1 of tin 1 that is, 4 atoms of iron and 1 of
tin. The first was very malleable, harder
than tin and not so brilliant ; the second but
moderately malleable and too hard to yield
to the knife. *
The formation of common tin-plate, is a
254 METALLIC ALLOYS.
proof of the affinity of tin and iron. Thin
plates of iron, thoroughly cleaned, are dip-
ped into melted tin, when the tin adheres to
the surface of the iron, forming with that me-
tal a true chemical union.
2. Iron and lead, &c. Iron combines by
fusion more or less perfectly with lead, zinc,
bismuth, antimony, arsenic, cobalt, manga-
nese, &c. but the proportions have in few
instances been ascertained, and the com-
pounds are generally of little importance.
Alloys of Nickel and other Metals,
Nickel and arsenic. As nickel and arsenic
are naturally found in combination, though
mostly along with small quantities of other
bodies, it is to be presumed that an* affinity
subsists between them ; but I do not know
that the proportions have been ascertained
inr which they unite, or the nature of the
alloys.
Alloys of Tin with other Metals.
I. Tin with lead. Tin and lead unite by
fusion in any proportion. This alloy, accord-
ing to Muschenbroek, is harder and much
PEWTER.
255
more tenacious than either tin or lead, espe-
cially when 3 parts tin and 1 lead are its con-
stituents,
I fused various proportions of tin and lead
together, as per the following table, in order
to find some of the more prominent charac-
teristics of the several alloys. The specific
gravity of the tin was 7.2, that of the lead
was 11.23; and the portions taken were such
as to combine, 1,2, or more atoms of tin with
1 of lead. The several metals were melted
and the compounds formed under a few drops
of tallow, otherwise the oxidation is so rapid
that the proportions are disturbed and the
quantity of pure alloy is not equal to the
weight of the ingredients. Without this
precaution it is no uncommon occurrence in
small experiments to obtain only 3 parts of
fusible alloy from 4 of metal.
Atoms.
Tin. Lead.
i + i
2 +
3 +
4 +
5 +
6 +
Weights
Sp. Gr. by
Sp Grby
calculation.
experim.
Tin. Lead.
.584-1
9.32
9.17
1.16+1
8.64
8.79
1.73+1
8.25
8.49
2. 3+1
8.00
8.10
2. 9+1
7.93
8.00
3.47+1
7.81
7.90
Fusing
Point.
430*
350
340
345
350
360
From the above table it appears that when
1 atom of tin is united to 1 of lead there is
an expansion of volume ; but when more than
256 METALLIC ALLOYS.
1 of tin are combined to 1 of lead there is a
contraction of volume, or the density is above
that by calculation. This increase of den-
sity is greatest when 3 atoms of tin are com-
bined with 1 of lead ; and it is not improbable
the tenacity may then be a maximum ; though
Muschenbroek finds it more tenacious when
3 parts tin are united to 1 of lead, which an-
swers more nearly to 4 atoms tin and 1 of
lead ; this opinion is countenanced by the fact
that tin is much the most tenacious of the two
metals taken singly.
It is remarkable that the fusing point of
these alloys is below those of either tin or lead.
The lowest of all (340°) is when 3 atoms of
tin are alloyed with 1 of lead.
Common pewter, 1 find, is &n allby of 4
atoms of tin and 1 of lead nearly, and fuses
about 345 or 350°. This is perhaps the best
proportion; it is hard, tenacious and of a good
colour. More of lead would impair the
colour, and more of tin would impair the
tenacity and increase the expence, though it
might improve the colour.
Certain articles for family use, such as tea-
pots, spoons, &c. are made of white metal,
which commonly, though I apprehend im-
properly, goes by the name of tutenag. This
metal in colour approaches more to silver than
TIN AND ANTIMONY. 257
pewter does. A spoon of this description
I found to be pure tin,
2. Tin and zinc. This alloy is easily made
by fusion. The metals seem to unite in any
proportion. I melted together 29 parts zinc
and 52 tin (1 atom of each), and obtained a
white hard alloy of about 6.8 specific gravity.
When 2 atoms tin and 1 zinc are united the
specific gravity is 6.77, which is below the
mean. The alloy appears to be very hard
and tenacious; and probably might be put to
some use.
3. Tin and bismuth. These metals readily
combine by fusion in any proportion. When
52 parts tin and 62 bismuth are fused toge-
ther (1 atom to 1), a fine, smooth, bard but
brittle alloy is obtained of the specific gravity
8.42. It fuses at 260°. Two atoms tin and
1 bismuth give an alloy of 8 specific gravity,
which fuses about 320°. The alloy of 1
atom tin and 2 of bismuth is of 8.67 specific
gravity, and fuses about 260°. The alloy of
3 atoms tin and 1 bismuth is of 7.73 specific
gravity, and fuses at 350°. The alloy of 1
atom tin and 3 bismuth is of specific gravity
9,14, and fuses at 330°
4. Tin with antimony. This compound is
said to be white and brittle when formed of
VOL. II. k k
258 METALLIC ALLOYS.
equal parts. I did not succeed in uniting the
two metals by fusion on a small scale.
5. Tin with arsenic* When 15 parts of
tin and 1 of arsenic are fused together the
alloy crystallizes in large plates like bismuth,
according to Bayen. It is brittle and less
fusible than tin. This alloy must be com-
posed of 5 atoms of tin and 1 of arsenic, that
is, 312 tin and 21 arsenic.
Alloys of Lead with other Metals.
1. Lead and zinc. These two metals seem
to have a weak affinity. They are easily
united, or rather mixed, in any proportion
by fusion under a little tallow. But however
they may be mixed there is a strong tendency
to separate again, which no doubt is occa-
sioned in part by their great difference in
specific gravity.
I have fused lead and zinc together in va-
rious proportions, from 6 parts ledd to 1 of
zinc, to 1 part lead to 2 of zinc. The com-
pound usually gives a specific gravity rather
greater than the mean ; but upon being bro-
ken the fracture is often like that of zinc in
one part and not so in another ; and the ana-
UEAD AND BISMUTH. 25&
lysis of fragments proves that a great differ-
ence exists in their composition. Subsequent
fusion sometimes improves the combination
and at other times the contrary. Six parts
lead and 1 of tin gave a compound as nearly
uniform as any. It was 1 1 specific gravity,
harder and whiter than lead and had much
the appearance of pewter, that is, the alloy
of tin and lead.
2. Lead and bismuth. These metals alloy
well. Three parts lead and 2 of bismuth
unite by fusion and form a tenacious alloy
which fuses about 340°. Muschenbroek
found it ten times stronger than lead. It
grows dark coloured soon by keeping. Its
specific gravity by my observation is 10.85,
which is rather greater than the mean. It is
constituted of 1 atom of each metal, or 62
bismuth to 90 lead.
Three parts lead and 4 bismuth (1 atom
lead to 2 bismuth) fuses at 250°. This is
the lowest temperature at which any alloy
of two metals fuses. With a little tin it
makes the triple alloy which fuses lower than
any other metallic compound, without mer-
cury, as will be shown in the sequel. The
specific gravity of this alloy of lead and bis-
muth is 10.7, which is greater than the mean.
The alloy of 1 part lead and 2 bismuth
260 METALLIC ALLOYS.
(1 atom of lead and 3 bismuth), fuses at
2^0°, and is of jO.1 specific gravity, or ra-
ther less than the mean.
The alloy of three parts lead and 1 bis-
muth (2 atoms of lead and 1 of bismuth)
fuses at 450°. The specific gravity is 11, or
rather greater than the mean.
3. Lead and antimony. These two metals
combine by fusion in any proportion. The
alloy is of a fine grain and is brittle or flexi-
ble as the antimony or lead prevails. The
principal use of this alloy, I believe, is in
the formation of printers' types. The small
types require a harder alloy or one with more
antimony ; the large types have a greater
share of lead as being less expensive. On
examination of the different types I find 3
proportions of the alloy principally in use.
The smallest types are cast from a mixture
which very nearly corresponds with 40 parts
of antimony to 90 of lead (or 1 atom to 1).
It is hard, has a fracture like steel and is of
the specific gravity 9.4 or 9.5 nearly, and
fuses about 480 or 500°. The proportions
were determined both by analysis and by
inference from the specific gravity of the
metal %
The middle sized types are made of metal
composed of 1 atom of antimony and 2 of
LEAD AND ANTIMONY. 261
lead, or 40 parts antimony and 180 of lead.
This alloy fuses about 450° or 460° and has
the specific gravity of 10 nearly.
The largest types or letters of 2 or 3 inches
diameter are made of metal composed of 1
atom antimony and 3 of lead, or 40 parts to
270. This alloy also fuses about 450 or 460°,
which is a very remarkable fact. Its specific
gravity is usually 10.22. After several trials
I could not determine whether the fusing
point of this or the preceding alloy was lower;
and equal parts of the two alloys fused toge-
ther were liquified at the same temperature of
450 or 460°.
All the intermediate sizes of types appear
to be made of one or other of the three pre-
ceding proportions or of mixtures of them,
the smaller the type the more of antimony
being required to give the requisite hardness.
The largest types might, I conceive, be made
with a much greater proportion of lead.
When 40 antimony and 360 lead (1 atom
to 4) are fused together, the melting point
is about 470° The specific gravity was
found 10.4, but probably too low from blis-
ters or air bubbles. The alloy was more flex-
ible than the preceding, but brittle with a
fine grained fracture.
Forty parts antimony with 450 lead (1
262 METALLIC ALLOYS.
atom to 5) fused at 490°, and gave 11 specific
gravity. This alloy bends and breaks with a
fine grained fracture.
Forty parts antimony with 540 lead (1
atom to 6) fused at 510°, and gave 10.8 spe-
cific gravity, which in all probability was
owing to air bubbles. Now the alloy soft
and malleable.
4. Lead and arsenic. When lead is fused
in contact with the white oxide of arsenic
under a film of tallow and stirred frequently,
an union of the two metals takes place and
the excess of white oxide is partially convert-
ed into arsenic and partly driven off, seem-
ingly taking with it a portion of the lead.
A considerable portion of the mass assumes
the form of a black spongy compound infusi-
ble at the temperature. It contains a portion
of the lead and is probably a compound of
the metals with oxygen. The fusible alloy
has the appearance of lead, but is brittle,
breaks without bending and exhibits a frac-
ture like that of antimony and lead. The
specific gravity of the alloy is 10.6, or more
if not saturated with lead. By treating it
with an excess of nitric acid it is dissolved,
and the lead may be thrown down by sul-
phuric acid, and the arsenic acid or oxide by
lime. In this way I find the alloy is com-
TRIPLE ALLOYS, 263
posed of about 9 parts of lead with 2 of ar-
senic, or 1 atom of each of the metals. The
spongy mass treated with nitric acid yields a
similar solution, accompanied with a precipi-
tation of oxide of arsenic,
5. Lead and cobalt. The alloy of these
two metals is not easily obtained, probably
from the great difference of the temperature
at which they fuse. Gmelin fused 1 part
cobalt with I, 2, 4, 6 and 8 parts of lead
respectively. Alloys were obtained of the
specific gravities 8.12, 12.28 (query 8.28 ?),
— , 9.65 and 9,78 respectively. From
these specific gravities it is plain the lead
had been in great part dissipated by the heat.
For the last or greatest specific gravity cor-
responds nearly to 2 parts lead and 1 of co-
balt. (An. de Chimie, 19—357.)
Triple Alloys, Solders ; Fusible Metal, fyc.
Though it may seem premature to treat
of triple compounds in the present chapter,
which professedly is limited to compounds of
two elements, yet as the triple alloys are few
and so immediately connected with the pre-
ceding, it will scarcely require an apology
for introducing them here.
264 METALLIC ALLOYS.
Soft solders. Solders for plumbers and
tin- workers, are required to melt easily, and
yet not too low, as they should withstand a
heat greater than boiling water. The fusing
point of the soft solders is usually between 3
400°. Plumbers' solder I believe is commonly
formed by mixing equal parts of tin and lead.
I procured a specimen of 8.9 specific gravity,
and its fusing point was 380? Probably a
more perfect compound would be formed by
mixing 104 parts tin with 90 lead (2 atoms
to 1), which would give a specific gravity
of 8.8 and the fusing point 350°.
Tin workers' solder is made rather more
fusible than that of the plumbers. A speci-
men I got from the Workmen was 8.87 spe-
cific gravity and fused at 345*. A mixture
of 3 parts tin and 2 of lead would have
formed an alloy of the same fusibility, but the
specific gravity would have been 8.6 or 8,7
only. Probably a rather less proportion of
tin with a little bismuth entered into the
composition.
Fusible Metal* Tin, bismuth and lead are
metals which melt at comparatively low tem-
peratures; and it has been shewn that the
alloys of any two of them usually melt at
lower temperatures than the mean, or even
than the lower extreme, By analogy it might
FUSIBLE METAL 265
be inferred that an alloy of tin and lead fused
with one of tin and bismuth, would melt
below either of the two ingredients. It has
been shewn that proportions of bismuth and
lead of easiest fusion are 2 atoms bismuth
with one of lead ; this alloy melts at 250*.
An alloy of 2 atoms of bismuth and 1 of tin
melts at 260°; and so does that of I atom
bismuth and 1 tin. These alloys being- much
more easily fused than any other proportions
of these metals, it is from their combinations
we are to expect a still further reduction of
the fusing* point. In fact, a combination of
either of the tin and bismuth alloys, with the
lead and bismuth alloy, produces almost
exactly the same reduction of the fusing
temperature.
Thus if 4 atoms of bismuth, 1 of tin and
1 of lead be fused together, the compound
melts in boiling water or below 212°. It is
equally the case if 3 atoms bismuth, 1 of tin
and 1 of lead, are fused together.
The double alloy next to those above men-
tioned in regard to easy fusion is that of 2
atoms tin, and 1 bismuth. It fuses at 320°.
This alloy, united to the one of 2 atoms bis-
muth and 1 lead, gives a compound of 3 atoms
bismuth 2 tin and 1 lead, which fuses very
LI
266 METALLIC ALLOYS.
nearly at the same temperature as the above
triple alloys.
In reference to weights, the above pro-
portions for the most fusible metals will
nearly be,
Bismuth 14 parts — Lead 5 — tin 3
10 5 3
5 2| 3
Most of the elementary books have given
the proportions of 8 bismuth, 5 lead and 3
tin; or 5 bismuth 2 lead and 3 tin, which
nearly agree with some of the above, and
give an alloy fusing below 212°.
Wishing to investigate this subject more
fully, and it being obvious from the prece-
ding facts that there are only two proportions
of tin and lead to be united with bismuth, to
produce the desired effect, namely, either 1
atom of tin with 1 of lead, or 2 atoms of tin
with 1 of lead, I proceeded as follows:
1 atom tin (52) + l atom lead (90) + l atom
bismuth (62), were fused together; the
fusing' point was 270°. The alloy was flex-
ible to a certain degree ; and the fracture
very small grained. To this alloy 31 grains
of bismuth were added successively till it
was evident the alloy was growing less fusi-
ble ; the results were as follows :
FUSIBLE METAL. 267
atom tin -f- 1 lead + 1 bismuth ; fuses at 270Q
1- i j- 1| 235«
— . (_ i |. 2 205°
f. 1 j- 2£ - 200°
j_ i 1_3 _. 197°
200°
220e
205° semi fluid.
240* semifluid.
but it retains a little fluidity down to nearly 200°
From this it appears that 3 parts by weight
of tin, 5 of lead, and any proportion of bismuth
from 7 to 14 will produce an alloy fusing
below 212°; but of these the best is 10 or
11 parts.
Again, 2 atoms of tin were combined with
1 of lead and 3 of bismuth, by gradually
adding one half of the tin. The several alloys
fused without any material difference at or
below 200«\ A further addition of tin im-
paired the property as in the above case with
bismuth. I did not think it important to mix
2 atoms of tin and 1 of lead with any other
proportion than 3 atoms of bismuth.
APPENDIX.
Since the publication of the second part
of the first volume, (1810) some important
essays on the subject of heat have appeared,
which have a direct bearing upon some points
of the doctrine on that subject inculcated in
the said volume. It may be proper to state
the results, with such remarks and reflections
as have occurred in the consideration of them.
In the Anuales de Chimie for January 1813,
also in the Annals of Philosophy, vol. 2, we
find a Memoir on the specific heat of different
gases, by M. M. De la Roche and Berard.
This exhibits a most laborious and refined
series of experiments on this most difficult
subject. Great merit seems to be due to
them, both for invention and execution.
It is unnecessary to describe the particulars
of the apparatus and the mode of conducting
the experiments, as a description may be
found as above referred. It is sufficient to
observe that the calorimeter used was a copper
cylinder of 3 inches diameter and 6 in length,
filled with water, and having a serpentine tube
5feet in length, running through the interior
and opening at both ends on the outside of
the vessels. By means of this tube a regular
current of any gas of a given temperature
SPECIFIC HEAT OF GASES.
269
(212°) might be passed through the vessel
so as to part with its excess of temperature
to the water. The quantity of water and the
capacity of the ve sel for* heat were previously
determined; and the quantity of heated gas
passed through the calorimeter was determin-
able at any time, as well as the temperature
of the water, from the judicious arrangements.
It is easy to see that when an apparatus of
this kind is at work, the gas will impart heat,
more or less according to its capacity, to the
water; and that the temperature of the ca-
lorimeter will gradually ascend till it arrives
at a maximum ; that is, till the refrigerating
effect of the surrounding atmosphere upon
the calorimeter is equal to the heating effect
of the current of iras.
The following Table exhibits the results of their
experiments.
Air
Hydrogen
Carbonic Acid ...
Oxygen.
Azote
Nitrous Oxide ...
Olefiant Gas
Carbonic Oxide...
Aqueous Vapour
Of the same bulk.
Specific Heat
1.0000
0.9033
1.2583
0.9765
1.0000
1.3503
1.5530
1.0340
1.9600
Of the same weight,
1.0000
12.3401
0.8280
0.8848
1 0318
0.8878
1.57.63
1.0805
3.1360f
f The result for this last article must be considered more
uncertain than any of the previous ones, the experiment
being more complicated.
270 APPENDIX.
They found the specific heats of equal vo-
lumes of air of the pressures 29.2 and 41.7
inches of mercury to be nearly as 1 : 1.2396,
differing from the ratio of the pressures or
densities, which is 1 : 1.358.
The above table of the specific heat of the
permanent gases (excluding aqueous vapour)
was corroborated by the results of another
series of experiments in which the principle
was varied a little : namely, to find how many
cubic inches of each gas at a given temper-
ature were required to raise the temperature
of the calorimeter a given number of degrees,
and inferring the capacities for heat to be
inversely as the quantities of gas employed.
The differences in the results were from 1 to
10 per cent, which may be considered small,
in experiments of such delicacy.
The ratios of the specific heats of several
gases being found, it was highly expedient to
find the ratio of the specific heat of water,
and that of some one gas, as common air.
This was effected by passing a small current
of hot water through the calorimeter, and
comparing the effect of this current with that
of the larger one of air, the requisite care
being taken to ascertain the quantity of water
passing in a given time and its temperature
at the ingress. The result of this experiment
was that the specific heat of water is to that
SPECIFIC HEAT OF GASES. 271
of common air as 1 : .25 nearly. By two
other experiments, varied from the above,
results not much differing were obtained, so
that the average of the three gave, water to
air, as 1 : .2669.
Reducing the specific heats of the gases to
the standard of water as unity, we have the
following Table of the specific heats of equal
weights of the respective bodies:
Water 1.0000
Air 0.2669
Hydrogen 3.2936
Carbonic Acid 0.2210
Oxygen 0.2361
Azote 0.2754
Nitrous Oxide 0.2369
OlefiantGas ......0.4207
Carbonic Oxide.. .0.2884
Aqueous Vapour 0.8474
Before we animadvert upon these results,
it will be expedient to give an abstract of the
not less interesting experiments of Messrs.
Dulong and Petit, on heat, as given in the
Annales de Chimie and de Physique, vol. 7
and 10.
These gentlemen begin by an investigation
of the expansion of air by heat. The abso-
lute expansion of air from freezing of water
to boiling had been previonsly determined by
272
APPENDIX.
Gay Lussac and myself to-be from 8 to 11
nearly: they however extended the enquiry
above and below these points of temperature,
namely to those of freezing' and boiling- mer-
cury. From the temperature of freezing- mer-
cury or thereabouts, to that of boiling water,
they find the expansion of air to keep pace
with that of mercury, as indicated by the
common thermometer ; but from the boiling-
point of water to that of mercury, the latter
expands somewhat more in a proportion gra-
dually increasing : as by the following Table.
TABLE I.
Temperature byan
air Thermometer,
Temperature by Mercurial
Corresponding vo-
corrected for ex-
Thermometer.
lume of a given
mass of air.
pansion of glass.
Fahrenheit.
Centigrade.
Centigrade.
-33°
-36°
0.8650
-36«
32
0
1.0000
0
212
100
1.3750
100
302
150
1.5576
148.70
392
200
1.7389
197.05
482
250
1.9189
245.05
572
300
2.0976
292ft)
680
M. boil 360
23125
350.00
The absolute dilatation of mercury claims
their attention. They quote nine authorities
for the expansion from freezing to boiling
water temperatures; the extremes of these
nine are, Casbois ^T of original volume, and
mine TV of the same. They determine it to
ON EXPANSION BY HEAT.
273
be T|vr. By doubling and tripling the ele-
vation of the temperature, they made obser-
vations from which are deduced the results of
the following Table. The dilatations are for
each degree of the thermometer centigrade,
to which I have added the corresponding
ones for Fahrenheit's.
TABLE II.
Temperature by an air
Thermometer.
Mean absolute dilata-
tions of mercury.
Temperatures indicated
by dilatation of mercu-
ry, supposed uniform.*
Fahr. Cent.
32° 0°
212 100
392 200
572 300
Fehr.
0
I
Cent.
0
TTTS
i
Fahr. Cent.
32* 0°
212 100
•
400.3 204.61
597.5 314.15
S"9 0'6'
I
9945
By a series of observations on the apparent
dilatation of mercury in glass vessels, com-
pared with the results in the above tables,
they deduce the absolute dilatation of glass
for each degree of the thermometer, and the
temperature that would be indicated by sup-
posing the uniform expansion of a glass rod
* That is, the temperature that would be denoted by-
mercury inclosed in a vessel having no expansion by heat;
or else in one that expanded in the same rate as mercury.
M m
274
APPENDIX.
adopted as the measure of temperature as
under :
TABLE III.
Temperature by
an airThermon;.
Fahr. Cent.
212° 100°
392
572
200
300
Mean apparent
dilatation of mer-
cury in glass.
Fahr. Cent.
TTFFT 6 TFo
TI4T3- 6?T?
1
Absolute dilata-
tion of glass in
volume.
Cent.
Fahr
i i
"5"sT4o T5To~o
ii i
Temperature by
a Thermometer
made of glass.
Fah, I
212
415.8
667.2
I Cent.
100
213.2
352.9
The absolute dilatations of iron, copper,
and platina were investigated with great ad-
dress, from 0Q to 100° and from 0° to 300°
centigrade ; and were found as per Table
below, for each degree of the centigrade
thermometer.
. TABLE IY.
Temp.by
the air
Therm.
Cent.
100s
300
Meandil-I
atation of Temp.by
iron, in iron rod
volume. I therm.
i£& \ 100°
&P& 372.6
Mean dil-
atation of
copper in
volume.
Temp.by
copper
rod ther-
mometer
Mean dil-
atation of
platina in
volume.
Temp.by
platina
rod ther-
mometer
i
100°
328.8
T7T-5T5-
100°
311.6
19400
TTTcro
Connected with this subject was another
important enquiry, whether the capacities of
bodies for heat remain constant at different
temperatures, or whether they diminish or
increase as the temperature advances. In
other words, does a body that requires a cer-
CAPACITIES FOR HEAT.
275
rain quantity of heat to raise it from 0* to
100° centigrade, require the same quantity
to raise it from 100° to 200°, and from 200
to 300°, &c; or does it require less or more
as we ascend ? This enquiry involves that of
the measure of temperature. They adopt the
uniform expansion of air, or the air thermo-
meter, as the proper measure, and find the
capacity of iron,
From 0* to 100° =k .1098
0 to 200 =r.ll50
0 to 300 = .1218
0 to 350 =.1255
the capacity of an equal weight of water
being 1.
The following Table exhibits the capa-
cities of seven other bodies according to their
results.
TABLE V.
Mean capacity
between 0° and
Mean capacity
between 0° and
Mercury
100°
300c
.0330
.0350
Zinc .........
.0927
.0507
.1015
.0549
Antimony ...
Silver
.0557
.0949
.0611
.1013
Copper
Platiua
.0335
.0355
Glass
.1770
.1900
276 APPENDIX.
According to this table the capacities of
bodies increase with the temperature in a
small degree: and the increase, though it
would still exist, would be less, if the com-
mon mercurial thermometer were the measure
of temperature.
Also supposing that thermometers made of
these bodies and graduated by immersion in
freezing and boiling water into 100° ; if these
were all immersed in a fluid in which an air
thermometer stood at 300°. Then the rela-
tive temperatures of the several thermometers
would be as under, if measured by the abso-
lute quantity of heat acquired, namely,
Iron 322? 2
Silver ... 329. 3
Zinc 328. 5
Antimony 324. 8
Glass 322. 1
Copper ... 320. 0
Mercury 318. 2
Platina... 317. 9
From these observations they infer that the
law which has been promulgated for the re-
frigeration of bodies, cannot be strictly true:
namely, that bodies part with heat in propor-
tion as their temperature exceeds that of the
surrounding medium.
Some animadversions on the general laws
relative to the phenomena of heat, announced
in my elements of Chemical Philosophy (page
13) then follow, together with a table drawn
LAWS OF REFRIGERATION. 277
up to show the discordance between the air
thermometer and the mercurial thermometer,
both being graduated in the manner I pro-
posed in the said elements. On these points
I may have to remark in the sequel.
The first part of the Essay concludes with
some remarks to shew why a preference should
be given to the air thermometer, or more
strictly, the thermometer whether of mercury
or any other body, supposed to be graduated
so as to correspond with an air thermometer
of equal degrees.
The Second Part of the Essay is on
The Laws of Refrigeration.
Adopting the air thermometer as the most
eligible measure of temperature, Messrs.
Dulong and Petit proceed to investigate the
laws of the refrigeration of bodies, under a
great variety of circumstances, in vacuo and
in air or gases of different kinds and densities.
The inquiry abounds with experiments and
observations evincing great skill and acute-
ness ; but which it will not suit our purpose
to detail. It may suffice for us to give a ge-
neral summary of the Laws deduced by them
from their experiments, at the same time re-
commending all those who feel sufficient in-
terest in the subject to peruse the essay at
large, which exhibits a profound philosophical
train of experiments, the results of which
278 APPENDIX.
are illustrated by the aid of mathematical
generalization.
" Law 1. If one could observe the cooling
of a body placed in a vacuum, and sur-
rounded by a vessel absolutely destitute of
heat, or otherwise deprived of the power of
radiating heat, the velocities of cooling
would decrease in geometrical progression
when the temperatures diminished in arith-
metical progression."
" Law 2. The temperature of a vessel con-
taining a vacuum being constant, and a body
being placed in it to cool, the velocities of
cooling for excesses of temperature in arith-
metical progression, decrease as the terms of a
geometrical progression diminished by a con-
stant number. The ratio of this progression
is the same for the cooling of all kinds of bo-
dies, and is equal to 1.0077."
" Law 3. The velocity of cooling in a
vacuum for the same excess of temperature,
increases in geometrical progression, the tem-
perature of the vessel circumscribing the va-
cuum increasing in an arithmetical progres-
sion. The ratio of the progression is the
same as above, namely 1.0077 for all kinds of
bodies."
" Law 4. The velocity of cooling due to
the sole contact of a gas is entirely independent
of the nature of the surface of the cooling
bodies."
LAWS OF REFRIGERATION 279
" Law 5. The velocity of cooling* clue to
the sole contact of a gaseous fluid varies in
a geometrical progression, while the excess
of temperature itself varies in a geometrical
progression. If the ratio of this second pro-
gression be 2, that of the first is 2,35, what-
ever be the nature of the gas and its elastic
force.
"This Law may be likewise announced by
saying that the quantity of heat carried off
by a gas is in all cases proportional to the ex-
cess of the temperature of the heated body
raised to the power whose index is 1.233."
" Law 6. The cooling power of a gaseous
fluid diminishesin a geometrical progression,
when its tension itself diminishes in a geome-
trical progression. If the ratio of this second
progression is 2, the rate of the first is 1.366 for
atmospheric air; 1.301 for hydrogen ; 1.431
for carbonic acid ; and 1.415 for olefiant gas."
"This law may also be presented as follows:
The cooling power of a gas, all other things
being alike, is proportional to a certain pow-
er of the pressure. The exponent of this
power depends on the nature of the gas, and
is for air 0.45; for hydrogen 0.315; for car-
bonic acid 0.517; and for olefiant gas 0.501."
"Law 7. The cooling power of a gas va-
ries with its temperature in such a manner
that if the gas can dilate so as to preserve
the same uniform tension, the cooling' power
will be as much diminished bv the rarefaction
280
APPENDIX.
of the gas, as it is increased by its augmen-
tation of temperature; so that definitively it
depends only on its tension."
Another ingenious Essay was published by
Messrs. Dulong and Petit, in the Annal. de
chimie et de physique, vol. 10, namely,
" Researches on some important points of the
theory of heat.'7 — One object is to ascertain
the specific heats of bodies with superior pre-
cision. A table of the specific heats of cer-
tain metals, found by their method, is given,
together with the weights of the atoms of
those metals, and the products of the specific
heats and weights of the atoms, as under:
Specific heats,
that of water
being 1
Weights of the
atoms, that o!
oxygen being 1
Pioductof the
weight of each
atom by the
corresponding
capacity.
Bismuth.....
0.0288
13.300
0.3830
Lead
0.0293
0.0298
0.0314
12.950
12.430
11.160
0.3794
0.3704
0.3740
Gold
Platinum ...
Tin
0.0514
0.0557
7.350
6.750
0.3779
0.3759
Silver
Zinc
0.0927
0.0912
4.030
4.030
0.3736
0.3675
Tellurium...
Copper
0.0949
3.957
0,3755
Nickel
0.1035
3.690
0.3819
Iron
0.1100
0.1498
3.392
2.460
0.3731
0.3685
Cobalt
Sulphur ....
0.1880
2.011
0.3780
SPECIFIC HEATS. 281
The inference intended from this Table is
pretty obvious, namely, that the atoms or
ultima! e particles of the above bodies contain
or attach to themselves the same quantity of
heat, or have the same capacity. This prin-
ciple the authors think will apply to the sim-
ple atoms of all bodies, whether solid, liquid,
or elastic; but they hold it-does not apply to
compound atoms. It differs therefore essen-
tially froma suggestion of mine, made eighteen
years ago, (see Vol, I. page 70,) that the
quantity of heat belonging to the ultimate par-
ticles of all elastic fluids, must be the same
under the same pressure and temperature.
They seem to apprehend, from experience,
that a very simple ratio exists between the
capacities of compound atoms and that of the
elementary atoms. They draw another in-
ference from their researches, that the heat
developed at the instant of the combination
of bodies, has no relation to the capacity of
the elements; this loss of heat, they argue,
is often not followed by any diminution in
the capacity of the compounds. They seem
to think that electricity developes heat in the
act of combination; but they do not deny
that a change of capacity may sometimes
ensue, and heat be developed from this cause.
N n
'282 APPENDIX.
Remarks on the above Essays.
Results nearly agreeing1 with those of De
la Roche and Berard, on the capacity of
certain elastic fluids for heat, were about the
same time obtained by M. M. Clement and
Desormes. (See Jonrnal de Physique, Vol.
89 — 1819.) Such results, impugning some
of the most plausible doctrines of heat, could
not be admitted but upon very good authority.
I remained doubtful, in some degree, till sa-
tisfied by my own experience. I procured a
calorimeter of the construction of De la
Roche's, and to simplify the experiment,
instead of forcing a given volume of hot air
through the calorimeter to impart heat to the
water, I drew, by means of an air-pump, a
certain volume of atmospheric (or other air)
of the common temperature, through the ca-
lorimeter filled with hot water, in order to
find how much this process would accelerate
the cooling. From several experiments of
this kind, I am convinced that the capacity
of common air for heat is very nearly such as
the above ingenious French chemists have
determined. That is, it is about * part only
of what Dr. Crawford deduced from his ex-
SPECIFIC HEATS. 283
periments, and nearly the same part of what
I inferred from my theoretic view of the spe-
cific heats of elastic fluids. (See Vol. I.
pages 62 and 74.)
Indeed M. M. De la Roche and Berard
appear to have been puzzled with the admis-
sion of their own results. The combined
heats of oxygen and hydrogen gases give
only ,6335 for the specific heat of water;
whereas by experiment the heat of water is
found to be 1, notwithstanding an immensity
of heat is evolved during the combination of
these gases, f
" It is necessary therefore," they observe,
" to abandon the hypothesis which ascribes
the evolution of heat in cases of combination
to a diminution of specific heat in the bodies
combined, and admit with Black, Lavoisier,
and Laplace, and many other philosophers,
the existence of caloric in a state of combi-
nation in bodies." I am not aware of any
writer that denies the existence of caloric in
a state of combination of bodies. Dr. Craw-
ford, who would be thought the most likely
to err in this respect, maintains, "that ele^
f By recent experiments I find the heat evolved in
the union of oxygen and hydrogen, would raise the tern-,
perature of the same weight of water 65001
284 APPENDIX.
mentary fire is retained in bodies partly by
its attraction to those bodies and partly by the
action of the surrounding' heat," and that
"its union with bodies will resemble that
particular species of chemical union wherein
the elements are combined by the joint forces
of pressure and of attraction." (On animal
heat, 2d edition, page 436.) He is perhaps
somewhat unfortunate in his instance in the
combination of carbonic acid and water;
muriatic acid or ammonia and water would
have been more in point.
The truth is, these important experiments
shew that in elastic fluids the increments of
temperature are not proportional to the whole
heat, compared with the like increments of
temperature and whole heat in those bodies
when in the liquid and solid states.
The specific heats of bodies, it is well
known, are determined by means of the re-
lative quantities of heat necessary to raise the
temperature of those bodies a certain number
of degrees. They are expressed by the ratios
of those quantities. If the capacities of the
same bodies for heat were permanent at all
temperatures, then these ratios would also
express those of the whole quantities of heat
in bodies. In fact, most authors represent
SPECIFIC HEATS. 285
the specific heats as expressing both the ratio
of the total quantities of heat in bodies, and
of the relative quantities to raise their tem-
perature a given number of degrees; but it
is the latter only which they accurately re-
present, and the former only hypothetically.
In regard to bodies in the solid and liquid
forms, all experience shews that their capa-
cities for heat are nearly if not accurately
constant within the common range of tem-
perature ; it seems therefore not unreasonable
to infer that the whole quantity of heat in
each is proportional to their increments.
When, however, a solid body by an increase
of temperature assumes a fluid form, and ab-
sorbs heat without any increase of its tem-
perature, its total quantity of heat is thus in-
creased; and it is contended by the writers
on capacity, that the increments of heat after-
wards are increased in the same proportion
as the total quantities. This is probable
enough ; but it ought to be proved in several
instances by direct experiment before it can
safely be admitted as a general principle;
more especially now since the analogy in the
case of a liquid becoming an elastic fluid is
found to fail in this particular. As an in-
286 APPENDIX.
stance of uncertainty, the capacity of ice to
water has been found as 9 to 10 by one per-
son, and as 7.2 to 10 by others; such wide
difference in the results shows there must be
a difficulty in determining' the specific heat
of ice, and that it may even be doubted
whether the specific heat of ice or water is
greatest.
From the foregoing detail of experiments
on elastic fluids, it appears evident that such
fluids exhibit matter under a form in which
it has the greatest possible capacity for heat,
when capacity is understood to denote the
total quantity of heat connected with the
fluid; but if the capacity or specific heat is
meant to denote the quantity of heat neces-
sary to raise the body a given number of de-
grees of temperature, then the elastic fluid
form of matter is that which has the least
capacity for heat of any known form of the
same matter. When therefore we use the
terms specific heat as applied to elastic fluids
we should henceforward carefully distinguish
in what sense they are used ; but the terms
may still be indifferently used in the one or
the other sense as applied to liquids and solids,
till some more decisive experiments shew that
a distinction is required. Probably the ano-
SPECIFIC HEATS. 287
malies that have occurred in investigations of
the zero of cold, or point of total privation
of heat, are in part due to the want of ac-
cordance between the ratio of the total quan-
tities of heat in bodies, and the ratio of the
quantities producing equal increments of
temperature.
The greatest possible quantity of heat
which a given weight of elastic fluid can
contain is when the dilatation of the fluid is
extreme. For, condensation, whether arising
from mechanical pressure or from increased
attraction of the atoms of matter for each
other, tends to dissipate the heat, by increas-
ing its elasticity. Hence increase of tem-
perature, at the same time that on one ac-
count it increases the absolute quantity of
heat in an elastic fluid, diminishes the
quantity on another account by an increase
of pressure, if the fluid be not suffered to
dilate. This is well known from the fact
that condensation produces increase of tem-
perature in elastic fluids.
When it is considered that all elastic fluids
expand the same quantity by the same in-
crease of temperature, it might be imagined
that all of them would have the same capa-
city, or require the same quantity of heat to
288 APPENDIX.
produce that expansion. The results of De
la Roche and Berard do not seem 'to admit
of this supposition, though the differences of
the capacities of elastic fluids of equal vo-
lumes are not very great. There is a re-
markable difference too between their results
and those of Clement and Desormes, in re-
gard to hydrogen gas : namely, .9033 and
.6640; also in carbonic acid gas, 1.2583
and 1.5. The subject deserves further in-
vestigation.
In reference to the experiments of Dulong
and Petit, on the relative expansions of air
and mercury by heat, I have no doubt their
results are good approximations to the truth.
My former experiments were chiefly made
in temperatures between 32° and 2] 2°, and I
found, as General Roi had done, the expan-
sion of air to be somewhat greater in the
lower half than in the upper half of that in-*
terval, compared with mercury. On a re-
petition of the experiments, 1 think the dif-
ference is less than I concluded it to be, and
I find that the like coincidence of the air
scale and mercurial, continues down to near
freezing mercury; at least the difference will
not be so great as my new table of temper-
ature makes it at page 14. I have made
SPECIFIC HEATS. 297
with another has less affinity for it left.* It
is plain then that oxygen gas or any other
elastic fluid, may have a small specific heat
in the sense above defined, and yet have an
almost unlimited quantity of heat. I am not
aware of any one established fact that does
not admit of an explanation upon the hypo-
thesis that heat exists in definite quantities in
all bodies, and is incapable of any change,
except perhaps into one of the other equally
imponderable bodies, light or electricity.
* See Dr. Henry's note, Manch. Memoirs, vol. 5,
page 679.
o o
2£S
APPENDIX.
NEW TABLE
Forces of Vapours in contact with the generating
Liquids at different Temperatures.
(.--.
-, »— i Oi O >C N 00 H"; S 2
fe.|. J ' ~ O CO ^ OD CO ► "S -2 i
*| | ~cogoo* s -S 5 5
* l .s i
— « CO
- #
C <»
3
s
o.t^.t;
U-,
CO ©
=>
OiCDHNOO
O u
a;
f* »o O © O i> O*
-= £
-C
■ ~ tj5 ~i oi o"
O o
w 5
C
-«(N00
3 cu
1—1
5§
o
CO O CO CO
3 c«
—; ON c* c*
co co oi Tt? od
;§Jgg
<-< O* Tj<
Sfl
<N
^ **•
?
<a a S
o
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"•is 2
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i> iq
to S®
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«N»OOCOO
5 o
c
"- CO CO Cl -*
« a
fM
— <N
02
5, s
es a
c
' -h* Tf — * d .s s * •■§
rs o
s « c ;
OS cj <D «►»
> « +» o
1 1
5 1 - 3
to
° t, cy **
a) t9 -a 9
3 c H <*
S 8 S 5
-3 E 3 ©
cr1 O
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T3
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a te « £
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c <u S g
s» .2 £ 2 -S
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SgS COCOOiCOl^Olt^^ III
AIR AND VAPOUR.
290
TABLE,
Shewing the expansion of air, and the elastw
force of aqueous and ethereal vapour, at different
temperatures.
Temperat.
-28°
-20
-10
0
10
20
30
32°
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
Vol. of air.
420
428
438
448
458
468
478
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
Utmost force of
Weight of 100
Aqueous vapour.
Ethereal vapour.
cubic inches
of aqueous
Inches of Merc.
Inches of Merc.
vapour.
Grains.
.08
.12
.17
.24
.26
7.00
.178
.27
7.18
.184
.28
7.36
.191
.29
7.54
.197
.30
7.73
.203
.31
7.92
.209
.32
8.11
.216
.33
8.30
,222
.34
8.50
.229-
.35
8.70
.235
.37
8.90
.245
.38
9.10
.255
.40
9.31
.267
.41
9.52
.275
.43
9.74
.284
.44
9.96
.293
.46
10.18
.303
.47
10.41
.313
.49
1064
.323
.50
10.87
.329
.52
11.10
.341
.54
11.34
.354
.56
11.59
.366
,58
11.85
.378
300
Temperature Vol. of air
56'
57
58
59
60
61
62
63
64
65
66
61
68
69
70
71
72
73
74
75
76
77
78
79
80
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
APPENDIX.
Utmost force of
Weight of 100
Aqueous vapour.
Ethereal vapour.
cubic inches of
aqueous vap.
Inches of M.
Inches of M.
Grains.
.59
12.12
.384
.61
12.39
.396
.62
12.66
.402
.64
12.94
.414
.65
13.22
.420
.67
13.51
,432
.69
1380
.444
.71
14.10
.456
.73
14.41
.468
.75
14.72
.480
.77
15.04
.492
.80
15.36
.509
.82
15.68
.521
.85
15.90
.539
.87
16.23
.551
.90
16.56
.569
.92
17.00
.580
.95
17.35
.598
.97
17.71
.610
1.00
18.08
.627
1.03
18.45
.645
1.06
18.83
.662
1.09
19.21
.680
1.12
19.60
.700
1.16
20.00
.721
Applications of the above Table.
These tables will be found of great use in
reducing" volumes of air from one tempera-
ture or pressure to any other given one : also
in determining the specific gravities of dry
gases from experiments on those saturated
with or containing given quantities of aque-
ous or other vapours.
As several writers, and some of consider-
able eminence, have given erroneous or im-
perfect formulas on these subjects, more par-
USES OF THE TABLE. 301
ticularly with regard to the effect of aqueous
vapour in modifying the weights and volumes
of gases, it has been thought proper to sub-
join the following precepts and examples for
the use of those who are not sufficiently con-
versant in such calculations.
The 5th column of the above table, or
weight of aqueous vapour, is new, and may
therefore require explanation. Gay Lussac
is considered the best authority in regard to
the specific gravity of steam ; but it would
be well if his results were confirmed or cor-
rected, as they are of importance. Accord-
ing to his experience, the specific gravities
of common air and of pure aqueous vapour,
of the same temperature and pressure, are as
8 to 5, or as 1 to ,625. Now I assume that
100 cubic inches of common air, free from
moisture, of the temperature 60° and the
pressure of 30 inches of mercury, weigh 31
grains nearly. It is an extraordinary fact
that philosophers are not agreed upon the
absolute weight of a given volume of common
air. Most authors now assume the weight of
i 00 inches— 30.5 grains, whilst according
to my experience it is more than 31 grains.
If common air be assumed 31 grains, steam
would be 19| grains for 100 cubic inches, at
the same temperature and pressure, could it
subsist; but as it cannot sustain that pressure
302 APPENDIX.
at the temperature of 60° we must tlednct
according* to the diminished pressure, the ut-
most force of steam at 60° being* .65 parts of
an inch of mercury, we have 30 inches : 19^
grains : : .65 : .420 grains = the weight of
100 cubic inches of aqueous vapour at 60°
and pressure ,65 parts of an inch; which is
the number given above in the table. The
like calculation is required for any other
pressure : but in addition to this, there is to
be an allowance for the temperature from the
2d column: Thus, let the weight of 100 cu-
bic inches of steam at 32° be required. We
have 30 inch. : 19| grs. : : .26 inch. : .1679
grs.; the weight of 100 inches of steam at
60°; then if 480 : 508 : : .1679 : .178 grs-
= weight of 100 cubic inches of steam at
32° and pressure .26 parts of an inch, the
tabular number required.
Examples,
1. How many cubic inches of air at 60°
are equivalent in weight to 100 cubic inches
at 45° ?
By the column headed volume of air we
have this proportion, if 493 : 508 : : 100
inch. : 103.04 inches, the volume required.
2. How many cubic inches of air with the
barometer at 30 inches height, are equal in
weight to 100 cubic inches when the baro-
meter stands at 28.9 inches?
USES OF THE TABLE. 303
Ride, The volume of air being inversely
as the pressure, we have, 30 : 28.9 : : 100
inches : 96^- inches the answer.
3. How many cubic inches of dry air are
there in 100 inches saturated with aqueous
vapour, at the temperature of 50°, and pres-
sure 30 inches of mercury ?
Here the formula p~f applies, where p
P
denotes the atmospheric pressure at the time,
andy denotes the utmost force of vapour in
contact with water at the temperature.
Hence p = 30, f = .49 per table, and we
p 30 30 y5T^
98ft Per cent dry air.
& 14-g. vapour.
TOO
If the vapour of ether is assumed, theny* =
10.64, and we have Izl = 30-10.64 _ ¥^> _
p 30 30
•645, or 64f per cent dry air.*
35j- per cent ethereal vapour.
100
4. Suppose we find by trial the weight of
100 cubic inches of common air saturated
with vaponr at 60°, the barometer standing
at 30 inches to be 30.5 grains, and the weight
* The aqueous vapour in this case maybe considered as insignificant.
304 APPENDIX.
of hydrogen gas in like circumstances to be
2,118 grains; query the weights of 100 cubic
inches of each gas free from vapour, and
their specific gravities, the temperature and
pressure being as above ?
If 30.5 : 2.118 : : 1 : ,0894 = sp. gr. of
vapourized hydrogen, that of vapourized air
being 1. Subtracting .42 grs. (weight of
vapour per table) from 30.5 grs., leaves 30.08
grains; and subtracting .65 parts of an inch
from 30 inches, leaves 29.35 inches. Hence
100 cubic inches of dry air at the pressure of
29.35 inches, weigh 30.08 grains; and we
have 29.35 : 30 : : 30.08 : 30.746 grains, the
weight of 100 inches of dry air. Again,
subtracting .42 grs. from 2.118, leaves 1.698
grains = weight of 100 cubic inches of hy-
drogen of 60° and sustaining the pressure of
29.35 inches ; whence if 29.35 : 30 : : 1.698
: 1.736 grains, weight of 100 inches of dry
hydrogen ; and 30.746 : 1.736 ; : 1 : .05645
== sp. gr. of dry hydrogen, that of dry air
being unity. Or the results may be exhibited
as under:
Weight of 100 cubic inches. Sp. Gravities.
Vap. air 30.5 grains 1... 14.4
Vap. hydrogen 2,118 .0694 .... 1
Dry air 30.746 grains 1 17.7
Dry hydrogen L.736 — .05645 ....1
MIXED GASES. 305
FORMULA TOR DETERMINING THE PROPORTIONS OP COM-
BUSTIBLE GASES IN MIXTURES.
It frequently happens, especially in the
decomposition of vegetable substances by
heat, that the product consists of several
combustible gases in mixture, and it is de-
sirable to determine the proportions of each
of those which collectively constitute the
mixture. The following forms will be found
useful for this purpose.
1. Carbonic oxide and hydrogen. ,
Let x = the volume of carbonic oxide, y
— that of hydrogen, w = that of mixture, and
a = that of carbonic acid, produced by;
exploding the mixed gases with oxygen over
mercury.
Then the carbonic oxide, or. a? = a,
and the hydrogen, oy y = w — a.
2. Sulphuretted hydrogen and hydrogen.
Let x == the volume of sulphuretted hy-
drogen, y = that of hydrogen, w = that of
the mixture, and g = the oxygen spent in the
combustion of w.
Then because x +y —■ w,and \lx + \ y=y;
we have x = g — iw, and y= If w — y.
pP
306 APPENDIX.
3. Phosphuretted hydrogen and hydrogen;
also carburetted hydrogen and hydrogen, and car-
buretted hydrogen and carbonic oxide.
The notation being as above, we have x 4- y
= rv, and 2x + J y =a g (see page 171 ) : and,
2g-^w , Aw - 2(/
4. Olefiant gas and carburetted hydrogen.
The notation being as above, we have,r + y
= rv, and 3# -f 2y = </ ; whence x = g — 2rv
and y ±? 8rv-g.
5. Carburetted hydrogen, carbonic oxide and
hydrogen.
Let # = carburetted hydrogen, y == carbo-
nic oxide, z = the hydrogen, g = the oxygen
spent in the combustion of rv volumes of
mixed gas, and a = the carbonic acid pro-
duced.
Then x + y + z = rv,
x 4- \y +■ \z = g,
and 2x + y = a.
whencewehaveo* = -~^, y = — — ^ and
z = rv — a.
6. Olefiant gas, carburetted hydrogen and
carbonic oxide.
Let a == the olefiant gas, 3/ = the carbu-
retted hydrogen, and z — equal the carbonic
oxide, g = the oxygen entering into com-
MIXED GASES. 307
bination, and a = the carbonic acid produced;
also w = the whole volume as before.
Then we have x 4- y + z == rvf
and 2x -f y + z = a*
whence x = a — w,
4w — 5a + 2</,
# = 3
and z == |> (w + a- g).
7. Superolefiant gas^ carburetted hydrogen^
and carbonic oxide.
Let a; = volume of superolefiant, y = volume
of carburetted hydrogen, z = volume of car-
bonic oxide, g = the oxygen combining, a m
carbonic acid produced, and w == volume of
mixed gas.
Then x + y -\- z = m,
±hx + 2y + iz = g,
and 3x + y + z = a.
Whence x = a~^9
m
_ 3tt?-4fl+2g.
3 " 3
and z = 3t0-4^—
o •
* A gas found in oil and coal gas. See Manchester
Memoirs, toI. 4 (new series), page 73.
308 APPENDIX.
8. Super (defiant gas, carburetted hydrogen,
carbonic owide, and hydrogen.
This is the mixture of gases obtained by a
red heat from coal and oil, after being freed
from carbonic acid, &c, by the usual means.
This mixture requires a very complicated
formula, in consequence of the specific gra-
vities of the gases entering into the calculus.
The importance of the subject however may
be an apology for the labour.
Let x = vol. of superolefiant, S its sp. gr.
y = vol. of carb. hydrogen, f its sp. gr.
z = vol. of carbonic oxide, c its sp. gr.
& u = vol. of hydrogen, s its sp. gr.
C = specific gravity of the mixture, g ==
oxygen, a = carbonic acid, and w = whole
volume of mixture as before.
Then wehave x + y + z + u = w
A\ x -f % -h \z '+ iu = 9
3 x + y + & : = «
And Sx + fy + cz + su = Cm.
Whence u —
(3S + 5c-8f)a -(4c-4/) #-(33 + 6C-6/ -3c) w.
" " 8/ + c - 3 S - 6s
The value of the hydrogen being obtained,
it may be subtracted from w, and the remain-
der will be best divided into three portions,
by the preceding formula.
MIXED GASE&. 309
HEAT PRODUCED BY THE COMBUSTION OF GASES.
Subsequent experience to that detailed at
page 77, Vol, 1. has furnished the following"
more correct results of the heat produced by
the combustion of pure gases.
Hydrogen, combustion of it raises an equal volume
of water 69
Carbonic Oxide 4|
Carburetted Hydrogen, or Pond Gas 18
01e6antGas 27
Coal Gas (varies with the gas from 10p to) 16
Oil Gas (varies also with the gas from 12° to) ... 20
Generally the combustible gases give out
heat nearly in proportion to the oxygen they
consume. See note at the end of Vol. 4,
new series of the Manchester memoirs.
ABSORPTION OF GASES BY WATER, &C.
This curious subject has attracted much
less attention than it deserves. Very little
has been published relating to it since the
time of Dr. Henry's essays and my own, now
more than twenty years ago. The only
author I remember is M. Saussure of Geneva,
who published a similar essay about twelve
vears afterwards. See Thomson's Annals of
Philosophy, Vol. 6. He investigates the
310 APPENDIX.
quantities of gases absorbed by various solid
bodies, in a manner which I do not fully
comprehend ; he then treats of the absorption
of gases by liquids, adverting at the same time
to Dr. Henry's experiments and mine. My
enquiries were principally confined to one
liquid, water; but I made a few trials with
others, such as weak aqueous solutions of sails,
alcohol, &c, and observing no remarkable
differences, I concluded somewhat too hastily
that " most liquids free from viscidity, such
as acids, alcohol, &c, absorb the same quan-
tity of gases as pure water." Manchester
memoirs, new series, Vol. I. M. Saussure
however asserts that there are considerable
differences in liquids in this respect. He
finds sulphuretted hydrogen to be more ab-
sorbable by water than Dr. Henry and I did;
in this I find he is right. Water takes about
2| its bulk of this gas when pure \ and it
seldom had been obtained unmixed with hy-
drogen when Dr. Henry and I made our
experiments upon its absorption. In regard
to carbonic acid, nitrous oxide, and defiant
gas, M. Satissure nearly agrees with us ; but
his results with oxygen gas, carbonic oxide,
carburetted hydrogen, hydrogen and azote,
would prove that water absorbs twice the
DEUTOXIDE OF HYDROGEN. 311
quantities of each that we have assigned. I
have no doubt he is wrong in the less absorb-
able gases. In the case of absorption of
mixed gases, Saussure has given four exam-
ples, in which he finds the results to militate
against my theoretic view, as stated at page
201, Yol. 1. ; namely, that water takes the
same quantity of each in a mixed state as it
would do if they were separate, and in other
respects in like circumstances. But I have
shewn in the Annals of Philos. Vol. 7, 1816>
that his results coincide as near as any one
can expect with the views which I have all
along taken of this subject.
It will be seen, page 173, that another gas
has been found to coincide with olefiant gas
in absorbability; namely, phosphuretted hy-
drogen.
FLUORIC ACID. — DEUTOXIDE OF HYDROGEN.
In treating" of Fluoric acid, (Vol. 1, page
277) we came to the conclusion that this acid
was probably constituted of two atoms of
oxygen, and one of hydrogen, and have
figured it accordingly (Plate 5, fig. 38).
Subsequent experience however has shewn
that deutoxide of hydrogen, though it can
be formed synthetically, is not the same thing
812 APPENDIX.
as fluoric acid. We are indebted to M.
Thenard for the discovery of this curious
compound, the deutoxide of hydrogen or
oxygenated water. An ingenious memoir on
the subject was published by him in 1818, in
which the formation and the properties of this
compound are fully detailed. I had no small
satisfaction in 1822, when at Paris, in being
obligingly favoured by M. Thenard with a
view of the process of the formation, and of
the more distinguishing properties of this
singular liquid.
The nature of fluoric acid is still enveloped
in obscurity. My experience led me to adopt
the composition of fluate of lime to be 40
acid and 60 lime per cent. I had not then
seen Scheele's admirable essay on the subject.
From the 5th section of his 2d. essay on
fluor mineral, 1771, it may be deduced that
fluate of lime is composed of 72.5 lime and
27.5 acid per cent. In 1809 Klaproth, and
near the same time, Dr. Thomson found
about 67| lime and 32J acid per cent, in
fluor spar. They both erred, no doubt, as
I did, by not repeating the treatment of the
mineral with sulphuric acid often enough.
Since then most authors, as Davy, Berzelius,
Thomson, Stc, agree with Scheele nearly,
MURIATIC AND OXYMURIATIC ACID. 313
in assigning 27.5 acid, and 72.5 lime, in 100
parts of filiate of lime. My experience in
1820 gave me 1 per cent less of lime ; and
Dr. Thomson now finds about 1 per cent
more of lime than Scheele's analysis gives.
If we estimate the atom of lime at 24, that
of fluoric acid must be about 9, according
with the above proportion ; this is much be-
low 15, the weight of an atom of deutoxide
of hydrogen.
Should Sir H. Davy's view of fluate of
lime be found correct, its atomic constitution
would be one atom of calcium, the metallic
substance of which lime is the protoxide,
and one atom of fluorine, the name he has
assigned to the other element, which with
hydrogen is supposed to constitute the fluoric
acid. The atom of fluor spar would then be
1 atom of calcium, 17, united to one atom
of fluorine 16.
MURIATIC ACID. — OXYMURIATIC ACID, &C.
From the articles muriatic acid and oxymu-
riatic acid in the former volume, published
now 16 years ago, as well as from the ap-
pendix to said volume, in which sundry an-
imadversions are found on the fluctuating
opinions entertained in regard to these acids,
Qq
314 APPENDIX.
the reader will not be surprised to find some
further addition.
Three notions have been submitted to the
public in the last twenty years in regard to
the nature of muriatic acid. First, the gas
detached from common salt by sulphuric acid
has been thought to be the acid in a state of
purity, and constituted of a certain base or
radical united to oxygen; this was the notion
inculcated in the articles alluded to above.
Second, — it is stated as a fact that when ox-
ymuriatic acid and hydrogen in equal volumes
are united by the electric spark, a volume of
muriatic acid gas is the result equal to the
sum of both the other volumes, and that this
gas perfectly agrees with the gas obtained
from common salt by sulphuric acid ; this
suggested the idea that muriatic acid gas is
a compound of what has been called real or
dry muriatic acid one atom, and water one
atom. And, third, it is argued, that the ele-
ment we have called oxymuriatic acid gas, is,
for aught that appears, a simple body, and
consequently, that muriatic acid gas is the
real acid, and is constituted as above, of one
atom of hydrogen, and one atom of oxymu-
riatic acid (now called chlorine,) It is not
intended here to enter into a discussion of the
arguments and facts adduced in support of
NITRIC ACID. 31.5
the different conclusions. More experience
must be had before all the doubts and difficul-
ties are removed from the subject. But it
will be proper to illustrate these different po-
sitions by an example. For instance, com-
mon salt, muriate of soda or chloride of so-
dium. By the first notion 50 parts of dry
common salt will consist of one atom of mu-
riatic acid gas, 22, and one atom of caustic
soda, 28. By the second notion the same salt
will be formed of 30 parts of muriatic acid
gas, and 28 of caustic soda ; but 8 parts of
water evaporate when the salt is dried. By the
third view common salt consists of oxymuri-
atie acid, or chlorine and sodium, or the
metal of which caustic soda is the protoxide;
and 50 parts of salt will consist of 29 chlorine
and 21 sodium, or one atom of each.
NITRIC ACID — COMPOUNDS OF AZOTE AND
OXYGEN.
Since the account of nitric acid (Vol. I,
page 343) was printed, a change has uni-
versally taken place in estimating the weight
of the nitric acid atom, and of the proportion
of azote and oxygen in the same. This has
been effected chiefly by a more correct ana-
lysis of nitre than existed at that time. Nitre
is now found to consist nearly of 52 part*
316 APPENDIX.
acid and 48 parts potash per cent. Hence if
the atom of potash be 42, that of nitric acid
must be 45; for, 48 : 52 : : 42 : 45, nearly.
That is, the nitric acid atom consists of 10
azote + 35 oxygen by weight ; or of 2 atoms
of azote (according to my estimate) and 5
of oxygen. There appear to be two nitrous
acids) namely, the one which I have des-
ignated by that name, which may now be
called sub-nitrous, or as Gay Lussac terms it
pernilrous ; and the other what I considered
as nitric acid in the former volume, composed
of 1 atom azote, and % of oxygen.
Ileal nitric acid then is that combination
which is effected by uniting oxygen with a
minimum of nitrous ga&; or 1 measure of ox-
ygen with 1.8 nitrous gas, (See 'Vol. 1, page
328). The oxynitric acid, which I was led
to infer from the last mentioned combination,
(1 azote with 3 oxygen) does not appear to
exist. The Table of nitric acid (Vol, 1,
page 355) will require some correction. An
increase of about 4 per cent, should be made,
I apprehend, on the quantities of acid cor-
responding to the several specific gravities.
Since my former volume of Chemistry was
printed, several essays on the compounds of
azote and oxygen have been published, with
some new and some adtU^onal experiments,
AZOTE AND OXYGEN. 317
the chief of which may be seen in Sir H.
Davy's Elements of Chemical Philosophy,
the Annales de chimie et de physique, Vol. 1 ;
Annals of philosophy, Vol. 9 and 10; and
the Manchester Society's Memoirs, Vol. 4,
second series; also Dr. Thomson's first prin-
ciples of Chemistry. Notwithstanding all
that has been written on the subject, there
still appears uncertainty as to the number of
combinations formed by these two elements,
their relative weights, and the number of
atoms in the several compounds.
The results of an experiment I lately made
on the decomposition of nitrate of potash by
heat seem to be worthy of record, as I am
not acquainted with those of any other person
who has pursued the experiment to the same
extent. — 1 took an iron retort of 6 cubic in-
ches capacity, and cleaned it as well as I
could from carbonaceous matter which it had
previously contained, first by heating nitre
to redness for an hour or more in it, and then
Washing it repeatedly with water till the li-
quid came out tasteless, and ority mixed with
a little red rust ; I then put in 480 grains of
purified nitre, and having secured a copper
tube to the retort so as to be air tight, the
retort was put into a fire and gradually raised
to a red heat, and the fire was occasionally
318 APPENDIX.
urged with a pair of bellows, in order to
keep up a glowing red on the retort for nearly
two hours ; the air was received over water in
jars ; the first 4 or 5 inches were thrown
away, and the rest was preserved and trans-
ferred to a graduated jar ; the products were
examined in successive portions as under,
namely,
Inches.
1 produce, 85 cubic inches, 83 per cent pure = 70.5
2 5 77 = 3.85
3 25 50 e= 12.5
4 6 30 = 1.8
Total 121 Oxygen 88.65
Oxygen 88.65 = 30 grains.
Residue 32.35 === 10 grains.
About 1 per cent on the whole gas was car-
bonic acid, the rest oxygen and azote, the
weights of which would be nearly as above.
Towards the last the gas came very slowly,
and being of inferior quality, the operation
was discontinued.
The remaining contends of the retort were
diluted with water, and well washed till the
water ceased t$ shew alkali ; the liquid was
then concentrated and gave 1600 water grain
measures of the sp. gr. 1.153. There were
obtained also 64 grains of red oxide of iron
from the washing of the retort, containing
19 grains of oxygen.
AZOTE AND OXYGEN. 319
The liquid was divided into portions and
examined ; the original nitre consisted of
250 grains of nitric acid united to 230 of
potash = 480 grains. After the process there
appeared to be,
10 grains of carbonic acid united to 21 grains potash,
62 grains of subnitrous acid to - 84
134 grains nitric acid to ~ - 125
230
The quantity of carbonic acid was deter-
mined by lime-water : the quantity of potash
uncombined with nitric acid was found by
precipitating it by tartaric acid, and mani-
fested 105 grains of potash in the bitartrate
= that combined with the carbonic and sub-
nitrous acids; from which subtracting 21, it
was inferred the remainder 84 must have
been in union with subnitrous acid, or else
with nitrous acid ; the rest of the potash, not
being acted upon by tartaric acid, was under-
stood to be combined with nitric acid.
The quantity of subnitrous acid given
above, appeared somewhat hypothetical, till
it was confirmed by treating a portion of the
liquid with oxymuriate of lime solution of
known strength ; it was found that 32 grains
of oxygen were required to be combined with
the subnitrous acid, in order to restore it to
the state of nitric acid ; that is, when oxy-
320 APPENDIX.
muriate of lime, containing that quantity of
oxygen, was added to the liquid, and this
was afterwards rendered acidulous by the ad-
dition of sulphuric acid, neither nitrous va-
pour nor oxymuriatic gas was perceptible ;
but a greater or less quantity of the oxy mu-
riate being applied, and the liquid made
acidulous, the fumes of the one or the other
were abundantly manifest.
It remains to account for the oxygen.
There were 250 grains of nitric acid at first
in the nitre; of which 200 grains were oxy-
gen and 50 azote, nearly. One-fifth part of
the oxygen = 40 grains, corresponds to 1
atom of oxygen. Now the whole of the
oxygen derived from the nitre in the course
of the experiment, seems to be 30 grains in
gas, 7 grains in the carbonic acid, and ID
grains in the iron oxide, together equal to
56 grains. Now the azote and oxygen in the
gas collected, were very nearly in the pro-
portion of those elements in nitric acid ; so
that a portion of the acid (about ^) might
be considered as completely decomposed,
whilst the rest was only losing a small part
of its oxygen : this is remarkable, and I think
indicates that the carbonic acid (formed from
the carbon of the retort, or from the adhering
carbon) unites to the potash, expelling the wi-
AZOTE AND OXYGEN. 321
trous acid, which is immediately decomposed
into its elements azote and oxygen. This would
not however account for the whole of the
azote: for, 40 grains of nitric acid would he
united to 37 potash ; whereas we find only
21 potash with carbonic acid y and I cannot
believe that an error in the estimate of car-
bonate of potash could exist to that amount.
The fact, however, was, that the elements of
40 grains of nitric acid were found in the
evolved gas, and hence we have to account
for the remainder 210 grains. From this
there appears to have been expelled 26 grainy
of oxygen, nearly 19 and 7 as related above;
of which the 19 grains cannot be correctly
estimated by reason of the uncertainty as to
the real quantity of oxide formed during the
operation : there might be some left adhering
to the retort, or on the other hand there might
be more than the due share, derived from
former experiments. Supposing then, that
26 grains of oygen were extracted from the
nitric acid, the remaining acid would require
the same to be added to re-form the nitric;
but by the experiments with oxymuriate of
lime it seemed to require 32 grains of oxy-
gen. This difference wants an explanation ;
I believe the greater error must belong to
the 26 grains ; perhaps the truth might be
R r
322
APPENDIX,
approximated best by supposing both to be
30 grains. ,
When the liquid decomposed nitre is treated
with any acid, a gas is instantly expelled
which produces red fumes in the air ; it is
pure nitrous gas, which joining with the oxy-
gen of the atmosphere, generates nitrous acid
vapour. At the same time, no doubt, the
sub-nitrous acid is disengaged from the pot-
ash, but that part of it which is real ni-
trons acid (1 atom azote to 2 of oxygen) is
retained by the water, whilst the other part,
(l atom azote and 1 of oxygen) assumes the
gaseous form. In order to be satisfied re-
specting this point, I made several experi-
ments with the liquid over mercury : taking
a given portion of the liquid, and sending it
to the top of a graduated tube filled with
mercury, I passed up as much muriatic acid
as was sufficient to engage the potash ; im-
mediately there was a disengagement1 of
nitrous gas and carbonic acid gas, and after-
wards a slow evolution of gas, evidently aris-
ing from the liquid in contact with the mer-
cury. Wishing to ascertain the quantities, I
sent up 25 grain measures of liquid, and to
that nearly half its bulk of muriatic acid; in
2 or 3 minutes there was,
AZOTE AND OXYGEN. 323
1.1 cubic inch of gas. H. M.
1.4 in 0 45
1.5 1 5
1.7 2 45
1.75 7 45
1.78 9 45
The gas was washed in lime .water, and
lost .33 parts of an inch of carbonic acid ; the
rest, 1.45 cubic inch, was nitrous gas. It is
obvious that j of the nitrous gas, together
with the carbonic acid, was liberated in-
stantly ; the rest of the nitrous gas was due
to the nitrous acid, slowly acting upon the
mercury. At the end of the process, there
was a little black oxide floating upon the
mercury. Calculating from this, the whole
quantity of nitrous gas would be 31 or 32
grains, whereas it ought to have been 48 grains
to constitute 62 of sub-nitrous acid. It is
probable that whilst a portion of the subni-
trous acid is oxidizing the mercury, another
portion may be forming nitric acid and dis-
solving the oxide.
From some trials, I have reason to think
that even carbonic acid will expel nitrous
gas from the liquid sub-nitrite of potash. •
In the essay of Dr. Henry, already alluded
to, published in the 4th Vol. of the Manches-
ter Society's Memoirs, a new and interesting
discovery is made ; namely, that a mixture
324
APPENDIX,
of nitroiis and defiant gates, though not ex-
plosive by . an. electric spark, may still be
exploded by the more powerful impetus of a
shock from a charged jar. Dr. Henry has
adduced the results obtained in this way, as
corroboratory of those which shew the consti-
tution of nitrous gas to be 1 volume of azote
and 1 of oxygen united to form 2 volumes of
nitrous gas, (See page 507 of the Memoirs.)
Some time ago in repeating these experi-
ments of Dr. Henry, I found some extraor-
dinary circumstances attending them. After
determining that 1 volume of defiant gas
may be fired with from 6 to 10 volumes of
nitrous, I found a shock from ajar sometimes
inadequate to fire the mixture, which, how-
ever, when repeated a second or third time,
succeeded. This is not a novelty ; for, mix-
tures of olefiant gas as well as other gases and
Vapours, with a minimum of oxygen, fre-
quently require several sparks before the
explosion : but this case occurs at times with
nitrous and olefiant gas, when they are mixed
in the most favourable proportions for explod-
ing. The most remarkable circumstance,
however, was, that when a phial was filled
with the mixture of the two gases in the pro*,
portion of 1 volume olefiant to 6 or 7 nitrous,
(exclusive of small portions of azote), the
AZOTE AND OXYGEN. 325
decomposition of the nitrous gas and the com-
bustion of the olefiant were scarcely ever per-
fect ; and what increased the perplexity more,
was, the results obtained from the same mix-
ture scarcely ever agreed one with the other.
After about 80 experiments, I was inclined to
adopt the conclusion, that the uncertainty was
occasioned by the oblong form of the eudio-
meter. The spark or shock, in my eudiome-
ter, is imparted at one extremity of a column
of air, which is often 10 times as much in
length as in diameter : it mostly was found
that the larger the quantity of mixture ex-
ploded at once, the more imperfect and in-
complete was the combustion. I imagine
the intensity of heat is not sufficient to carry
on the combustion through the length of the
column, owing, perhaps, to the cooling power
of the sides of the tube. Hence it was, I ap-
prehend, that in one or two instances, when
a small quantity of gas was used, I got
nearly complete results, as Dr. Henry reports
his ; but in the majority both gases were
found in the residue after the explosion.
In pursuing this enquiry into the decompo-
sition of nitrous gas by combustible gases, I
found that it might be effected by any com-
bustible gas or vapour: at least it succeeded
in all I tried. The method I pursued, and
3^6 APPENDIX.
which was suggested by the known proper-
ties of phosphuretted hydrogen, is this: it
has been shewn (page 181) that a mixture of
phosphuretted hydrogen and nitrous gas ex-
ploded by an electric spark, the former gas
being completely burned in case the propor-
tions are duly adjusted ; now, it occurred to
me, that as the above combustible gas is usu-
ally a mixture of pure phosphuretted hydro-
gen and of hydrogen, and that the latter of
these is also burned as well as the former, the
effect must be produced through the heat
occasioned by the combustion of the former.
Having some old phosphuretted hydrogen by
me, at the time, which on examination, I
found to be 91 per cent, combustible gas, and
9 azote ; and the 9J combined with 156 of
oxygen, consequently was 74 pure, and 17
hydrogen ; I tried this mixture with nitrous
gas, when it exploded by the spark, as usual ;
but on trying it with an excess or defect of
nitrous gas, the spark was inefficient, but the
shock instantly fired the mixture. As there
did not appear to be any of the pure hydrogen
left unburned in these experiments, I pro-
ceeded to mix the old phosphuretted hydro-
gen with hydrogen ; and then this new mix-
ture with nitrous gas. The first experiment
was made with 4 parts of old phosphuretted
AZOTE AND OXYGEN. Ml
hydrogen 4- 16 hydrogen 4- #6 nitrous gas
= 56 total. On this mixture the spark, of
course, had no effect ; but it exploded the first
trial by the jar, and left 20 measures, of which
2 were found to be oxygen, and the rest azote.
This experiment succeeding so well, I next
tried mixtures of phosphuretted hydrogen,
with carbonic oxide, carburetted hydrogen,
and ether vapour successively, along with
nitrous gas ; and found that all these mix-
tures refused combustion by the spark, but
were instantly exploded by the shock, yield-
ing carbonic acid and water, the same as if
the combustion had been effected by free oxy-
gen. In some instances the combustion was
complete, leaving neither combustible gas
nor nitrous gas ; but generally there was a
residue of one or both of the gases.
From these experiments it may be con-
cluded that the heat, produced by the combus-
tion of phosphuretted hydrogen and nitrous
gas or oxygen gas, disposes other gases, acci-
dentally in the mixture, to chemical changes.
In conformity with this view, I mixed phos-
phuretted hydrogen and oxygen, in the pro-
portion of mutual saturation ; and taking a
small proportion of this mixture, and as much
ammoniacal gas as would saturate the phos-
phoric acid to be formed, I found that caus-
328 APPENDIX.
ing an explosion over mercury, the phospho-
ric acid combined with the ammonia, and
nearly the whole gas disappeared. In this
case, the heat was not sufficient to decom-
pose the ammonia. But in another experi-
ment, with a portion of the same explosive
mixture and a less proportion of ammonia,
after the firing a residue of azote and hydro-
gen was found, amounting nearly to the
quantity due from the decomposition of the
ammonia. Here the heat produced, had
evidently decomposed the ammonia.
ON AMMONIA.
The constitution of ammonia still remains
undecided. The latest experiments on this
article are those of Br, Henry, in his essay
on the analysis of the compounds of nitrogen,
(Memoirs of the Manchester Society, vol 4,
1824.) By electrifying ammoniacal gas over
mercury, as carefully as could be devised,,
Dr. Henrv found results as under :
] st experiment 44 measures became 88-f-
2d 157 320
3d 60 122
4th 120 240
The evolved gases carefully analysed by com-
bustion with oxygen, M'ere found to consist of
AMMONTA. 329
? volumes of hydrogen and 1 of azote. The
analysis of ammonia was also effected by ex-
ploding* it with nitrous oxide, with the requi-
site precautions. The results confirmed the
previous ones by electricity, both in regard to
doubling the volume of ammonia, and esta-
blishing the ratio of 3 to 1 in the volume of
hydrogen and azote. — These experiments are
highly interesting as far as regards the ques-
tion of ammonia, as they exhibit the latest
investigations of one who has previously
shewn uncommon skill and perseverance in
this kind of analysis. (See Philos. Transact.
1809, &c.)
Dr. Henry's analysis of ammonia, in 1809,
has been adverted to in our article on the
subject, vol. 1, page 429. The results of
that Essay are given in a tabular form ; and
the mean of six experiments was nearly as
we have stated, namely, that ammonia con-
sists of 27 J measures of azote, and 72 \ hydro-
gen. To this it may be proper to add, that
the two extremes were, 26.1 azote and 78.9
hydrogen, and 28.2 azote with 71.8 hydro-
gen ; also that a small error has crept into
the table, which being corrected, the average
results are reduced to 27 and 73, very nearly.
Subsequently, both Dr. Henry and Sir H.
Davy concurred in assigning 26 and 74 for
S s
$30 APPENDIX.
tlie most approximating numbers. (See
Nicholson's Journal, 25, page 153). The
true quantity of gases procured by the de-
composition of ammoniacal gas by electricity,
was concluded by both these authorities, to be
180 for each 100 of ammonia, when the re-
quisite precautions were taken, as we have
related in vol. 1.
From what is stated above, it is evident the
subject is one which requires extraordinary
skill and attention. This I can attest from
my own experience, which has been fre-
quently renewed and varied ; but the results
have not been sufficiently accordant to )ield
me satisfaction.
About ten years ago, I made several
experiments on the decomposition of ammo-
nia, which, though they are not convincing,
deserve, perhaps, to be recorded in their re-
sults.— Some more recent experiments are
incorporated with them.
Decomposition of ammonia by nitrous oxide*
— I made many experiments, by exploding
mixtures of nitrous oxide and ammoniacal
gases over mercury. The excess of gas was
mostly on the side of ammonia, but the pro-
portions were varied in the different experi-
ments, from 10 vol. nitrous oxide to 1 1 ammo-
AMMONIA. 331
s
nia or to £, which are about the extremes ca-
pable of being fired by the electric spark.
When 10 parts nitrous oxide and 5 of am-
monia are exploded over mercury, the resid-
uary gas contains some free oxygen and some
nitrous acid derived from the decomposition
of the excess of nitrous oxide used ; with 6
parts of ammonia there is rarely any free oxy-
gen. When 10 parts of nitrous oxide, and
7 of ammonia are fired, I never found any
free oxygen or hydrogen; but when the am-
monia is at or near 8 parts, I find from ™ to
-j-V of the hydrogen from the ammonia in the
residuary gases. The two gases appear to
be completely decomposed; the oxygen of
the nitrous oxide, as far as it can, unites
with the hydrogen of the ammonia, without
forming any portion of nitrous acid or of free
oxygen, and the residue contains the azote
of both gases, and the unburnt hydrogen from
the ammonia, as Dr. Henry first observed.
This continues to be the case till the am-
monia becomes 11 parts, when the hydrogen
amounts to about 4- of the whole quantity
which the ammonia yields.
From the above it would seem that the
proportions for mutual saturation must be 10
nitrous oxide with from 7 to 8 parts of am-
monia. This agrees with the deduction in
332 APPENDIX.
Dr. Henry's first essay that 13 nitrous oxide
require 10 of ammonia; or that 10 require
7.7 : but according to the theory of volumes
10 would require 6^; and Dr. Henry recom-
mends in his late essay 10 nitrous oxide to
7.7 or 8 1 parts of ammonia, in order to secure
a small excess of the last, and consequently
some free hydrogen after the explosion. The
former of these proportions would have nearly
4- of the residue hydrogen, and the latter
nearly j, supposing the gases pure originally.
Tins gives more hydrogen than 1 have ever
found ; but the azote in my experience nearly
agrees with the doctrine of multiple volumes.
Decomposition of ammonia by nitrous gas. —
About 30 experiments carefully made on
mixtures of nitrous gas and ammoniacal gas
gave very discordant results. At one time 10
parts nitrous gas with 14 ammonia gave -4-
of hydrogen in excess, and another time 10
nitrous with 12 ammonia gave excess of hy-
drogen = -?%; generally 10 parts with 6 or
less gave oxygen, and 10 with 8 or more gave
hydrogen in the residue.
Decomposition of ammonia by oxygen. —
The limiting proportions of oxygen and am-
monia which I have fired, are 10 oxygen to
4 ammonia for the minimum, and 10 oxygen
to 22 ammonia for the maximum. When 10
AMMONIA. &J3
oxygen were fired with 4 ammonia, there
were *f of the oxygen left, and there was a
deficiency of azote amounting to T^ of what
was expected from the ammonia, owing* no
doubt to nitrous acid generated by the explo-
sion. When 10 oxygen to 1.8, or from that
to 2.2 ammonia are used, there is a surplus of
about j or ■£ of the hydrogen contained in the
ammonia, left in the residue of the gas.
When the ammonia is between 13 and 14
there is usually a trace of oxygen or hydro-
gen as it approaches either of these limits.
By the theory of volumes, 10 oxygen should
saturate 13f of ammoniacal gas. 1 have not
any instance of hydrogen being left when 14
ammonia were used, though there ought to be
^J of the whole left; and much smaller quan-
tities than that are appreciable by well known
methods. The azote resulting from the de-
composition of ammonia is usually very nearly
| the volume of the ammonia.
On the whole the results from firing am-
monia and oxygen gas appear to me more
satisfactory than those obtained from nitrous
oxide and nitrous gas, as they are more sim-
ple and less perplexed with any theoretic
views.
It may be proper to remind the reader that
when we speak of 10 parts of one gas uniting
334 APPENDIX.
with 8, 10, or more, of another in the above
and other cases, it is to be understood of
gases absolutely pure ; not that we ever obtain
them in that state, but approximating as near
as we can to it, we mix given portions of
such gases as we can obtain, and then in our
calculations of results deduct for the impu-
rities.
One source of uncertainty in these experi-
ments on firing mixtures of ammonia, is that
the real quantity of ammooiacal gas operated
upon is not known. If a certain measure of
ammonia be transferred through mercury
ever so dry, some portion of it gets entangled
in the mercury, and 100 measures become
perhaps 95 : now in the explosion it is a ques-
tion whether any part of the 5 measures ab-
sorbed is decomposed. I have marked this
attentively, and am persuaded that generally
speaking, little if any of that portion is de-
composed ; but some trace of it appears mostly
afterwards in the residue as it is liberated from
the pressure of its own kind of gas, and hence
easily rises into the gaseous mixture. Not-
withstanding, when the loss of gas by trans-
fer amounts to 10 or 20 per cent, I have rea-
son to believe that some part of it suffers
combustion occasionally.
AMMONIA. 335
Volume of gases from the decomposition of
ammonia. — It has been observed (vol. I. Am-
monia) that Sir H. Davy obtained 180 mea-
sures of gases, by means of electricity, from
100 of ammonia as the maximum when the
operation was performed with great care, and
Dr. Henry in like circumstances, produced
181, whilst I found 187 measures; since that,
as has been related, Dr. Henry has found
200 measures. It is not easy to account for
these differences ; I am inclined to the opinion
that the volume of gases is very nearly dou-
bled, but probably rather less than more. I
find the experiments on the rapid combustion
of ammonia agree best with that opinion.
Decomposition of ammonia by a red heat. — •
A short time since I repeated the decomposi-
tion of ammonia by passing the gas through
a red hot copper tube. The proportion of azote
to hydrogen, due allowance being made for a
minute portion of atmospheric air, was upon
the average of a number of experiments, 26
of the former to 74 of the latter.
Decomposition of ammonia by oxy muriatic
acid. — I have made several experiments on
this mode of decomposition since the results
published in vol. 1, page 435. It is well
known that a solution of oxymuriate of lime
decomposes ammoniacal salts; water and
336 APPENDIX.
muriatic acid are produced, azote liberated,
and the acid previbusly combined with the
ammonia is evolved. But this is not all ; an
excessively pungent gas or perhaps vapour is
produced, exciting sneezing, and inducing
catarrh ; the constitution of this vapour is not
well understood ; it is never formed, as far
as I know, without the presence of both oxy-
muriatic acid and ammonia. The results of
such mixtures are of course complicated and
likely to be unsatisfactory ; it may notwith-
standing be useful to relate some of thenu
When clear oxymuriate of lime solution,
and a salt of ammonia are mixed together
with a little excess of oxymuriate, the am-
monia is mostly decomposed, the oxymu-
riate being converted into muriate of lime
by the hydrogen of the ammonia, whilst the
azote is evolved, and the acid previously
combined with the ammonia is liberated ;
hence oxymuriatic acid gas is also liberated
along with the azote ; and it is required to
be taken out before the azote can be estimated.
This circumstance may be obviated by pre-
viously adding the requisite quantity of pure
potash or soda, to engage the acid, or by
leaving a little undissolved lime in the oxy-
muriatic solution. I could never obtain a
volume of azote equal to half that of the am-
AMMONIA. 337
nionia (.-supposed lo he in a gaseous state)
though it is universally allowed not to be less
than that, if the whole of the azote be evolved ;
on one occasion only I got so much as 44 of
that quantity. The residue of liquid has the
extremely pungent smell ; but the azotic gas
after passing through pure water has no smell.
When this experiment is made over mercury,
the oxymuriatic acid acts upon it, and hence
the excess of oxy muriate should be such as to
leave a portion of that undecomposed at the
conclusion.
When the object is to ascertain the hydro-
gen in ammonia, a portion of salt known to
contain a given weight of ammonia is to be
treated with oxymuriate of lime solution, the
strength of which is accurately determined by
means of green sulphate of iron, or otherwise.
The ammoniacal salt in solution is then to be
mixed with a moderate redundance of the
oxymuriate liquid, and with a few drops of
caustic potash, and the mixture must be re-
peatedly agitated for some time. At length
the liquid must be tested by the green sul-
phate of iron, and hence the quantity of acid
spent upon the ammonia will be determined.
I have mostly found the hydrogen this way
below the common estimate, allowing the
ammoniacal salts to be correctly determined.
T t
338 APPENDIX.
&ULPHURET OF CARBON.
Since the article at page 462, vol. 1, was
written, an excellent essay on the sulpburet of
carbon has been published in the Philosophical
Transactions, (IB 13) by Professor Berzelius
and Dr. Marcet. After an extensive series of
experiments, they infer the atom of the sul-
phuret to consist of 2 atoms sulphur and L of
carbon. The investigation did not seem to
warrant their including* hydrogen in the atom.
I have made several experiments on the com-
bustion of the vapour of sulphuret of carbon
in oxygen gas by electricity. My method
generally was, to vapourize a given portion
of atmospheric air over mercury, taking care
that the vapour was below the maximum for
the temperature ; this is easily effected by
petting the liquid into a phial of air, drop by
drop, and inverting it over mercury till the
liquid is evaporated. This vapourized air, I
find may be transferred through mercury with
very little loss, and even through water se-
veral times, without a total condensation of
the vapour. The vapour of ether is much
more coiiUensible by water than that of sul-
phuret of carbon. A given portion of this
vapourized air is to be mixed with oxygen
gas, in Volta's eudiometer, and then exploded
STJLPHURET OF CARBON. £89
by the electric spark over mercury. One vo-
lume of vapour combines with nearly 3| of
oxygen, and therefore requires 4 or 5 times
its bulk of that gas before firing, in order
that the combustion may be complete. The
results of the combustion are carbonic acid
and sulphurous acid ; and I suspect a small
portion of water; though Professor Berze-
lius and Dr. Marcet could not detect any.
By evaporating a given weight of the sul-
phuret of carbon, in. a given volume of at-
mospheric air, at the temperature of 60°, I
find the specific gravity of the vapour to be
2.75 nearly, air being 1. Now if we assume
the atom of vapour to be nearly of the same
volume as that of hydrogen, and to consist of
1 atom hydrogen, 2 sulphur, and 1 carbon,
it will require 7 atoms of oxygen to form
water, sulphurous acid, and carbonic acid,
which will accord very well with my experi-
ence. When vapourized hydrogen gas is
electrified for some time, there is no change
of volume, though there is some appearance
of decomposition. Probably the hydrogen
of the sulphuret is liberated. It is difficult
to conceive how so volatile a liquid as the one
in question, could be constituted out of suL-
phur and carbon without the addition of
hydrogen.
340 APPENDIX.
POTASSIUM, SODIUM, &C
Two views of the nature of these bodies
have been given in vol. 1, (see pages 260, and
484, &c). In the, former they are considered
as simple metals; in the latter, as compound
bodies resulting from the abstraction of oxy-
gen from the hydrates of potash and soda ;
or as being constituted of 1 atom of hydrogen
united to 1 atom of pure potash or soda res-
pectively. Those who have had the most ex-
perience on these elements, Sir H. Davy,
and M. M. Gay Lussac and Thenard, seem
now to concur in the former view, and it has
been adopted by most chemists. Part of the
objections which we made to this view have
been obviated, it should seem, by establishing
the fact, that oxymuriatic gas and hydrogen
gas united, form muriatic acid gas. There
are still, however, difficulties to remove before
this view can be considered perfectly satis-
factory ; but they are not greater perhaps
than would attach to any other explanation
of the facts connected with the subject. Be-
sides potassium and sodium, experience as
well as analogy would seem to render proba-
ble, if not to establish, the existence of ba-
rium, strontium, and calcium as metals, of
which barytes, strontites, and lime are the
ALUM. 841
protoxides, as potash and soda are of the
other two metals ; (other oxides of potassium
and sodium are stated, see page 55 — 57);
barium has a deutoxide, and probably cal-
cium likewise. The rest of the earths, as
magnesia, alumine, silex, &c. are by analogy
considered by most chemists as oxides of
particular metals, but the proportions of their
elements have not been determined.
ALUM.
At page 581, vol. 1, we have given the
constitution of this important salt, as under :
since that time Mr. R. Phillips has announ-
ced another view of it ; and Dr. Thomson
has published one differing from both of these.
They are as follow : *
Dalton — 1 atom sulphate of potash.
4 atoms sulphate of alumine.
30 atoms water.
Phillips — 1 atom bi-sulphate of potash.
2 atoms sulphate of alumine.
22 atoms water.
Thomson — 1 atom sulphate of potash.
3 atoms sulphate of alumine.
25 atoms water.
342 APPENDIX.
Notwithstanding' these differences, there is
a near approximation in all three, in regard
to the quantities of acid, alumine, potash,
and water in the salt. This is accounted for
partly in the different relative weights of the
atoms, as estimated by the different analysts,,
but chiefly in that of alumine.
Some very curious results occurred to me
about 10 years ago in analysing' alum; they
were new to me, but I have since found they
had been previously discovered by Scheele.
(See his essay on silex, clay, and alum, 1776.)
As his observations are not to be found in any
of our elementary books that 1 have seen, I
shall give the particulars of my own experi-
ments here.
I take 24 grains of alum and dissolve them
in water; of these 8 grains may be allowed
for sulphuric acid, -j of which = 1.6 grain
— 1.1 grain of lime — 880 -grains of lime-
water, such as I commonly use. To the so-
lution of alum I put 880 grains of lime-water ;
a slight precipitate appears which soon be-
comes redissolved almost completely. The
liquid is then acid by the colour test.
To this liquid I put 880 more of lime-water,
and agitate; a copious precipitate appears
and continues ; after subsidence the clear li-
quid is stiil acid by the colour test.
alum. ms
Another 880 grains are added*, and the
whole is then well agitated ; the agitation is
repeated two or three times after the precipi-
tate has partly subsided, so as to diffuse it
equally again through the liquid; finally, the
clear liquid is found to be neutral by the co-
lour test, and to contain no alumine; for,
lime-water produces no precipitate when
poured into it.
Another 880 grains being added, and the
whole stirred well, the clear liquid after the
subsidence of the precipitate is still neutral
by the colour test.
The fifth portion of 880 grains being then
added, and the mixture well agitated, a con-
siderable portion of the precipitate will evi-
dently disappear, and the mixture become
semitransparent ; after a time the clear super-
natant liquid is found strongly alkaline ; a
little of it touched with an acid becomes
milky, and adding more acid clears it again.
The liquid is now 1.0025 sp.gr., or a little
heavier than lime-water.
The sixth portion of 880 grains being now
added to the whole mixture, and agitated,
the precipitate rather diminishes, and an in-
crease of specific gravity takes place in the
liquid: it is now 1.003.
844 APPENDIX.
The seventh and last portion of 880 grains
being added to the mixture, and agitation
being continued for some time, a dense bulky
precipitate is formed, which falls with great
celerity, carrying with it the greatest part
of the acid, the alumine and the lime, and
leaving the liquid of the sp. gr. 1.0012. It
is a subsulphate into which acid, potash, lime
and alumine enter, as will be shewn.
These phenomena appear to me to be best
explained by adopting a constitution of alum,
such as to make it consist of 1 atom bisul-
phate of potash and 3 atoms of sulphate of
alumine; after which the following explana-
tion will apply.
The first portion of lime-water saturates
the excess of acid.
The second portion throws down a corres-
pondent portion of alumine. The clear liquid
is acid, because it contains sulphate of alu-
mine, which is essentially acid by the colour
test, because alumine is not an alkaline ele-
ment.
The third portion throws down another
portion or atom of alumine ; but by conti-
nued agitation the two atoms of alumine liber-
ated, join the remaining atom of sulphate of
alumine, and the whole compound falls down,
being then the common subsulphate of alum.
ALUM. 345
Hence the* liquid, containing nothing" but
sulphate of lime and sulphate of potash, is
neutral by the test, and yields no alumine by
the addition of lime-water.
The fourth portion of lime-water being
put in and duly agitated, the atom of sul-
phuric acid is drawn from the subsulphate to
join the lime, and then the floating subsul-
phate of alumine becomes pure alumine, and
the clear liquor is still neutral.
The fifth portion of lime-water tries to de-
compose the sulphate of potash, but is unable
of itself; however, the floating alumine as-
sits it, and by double affinity the potash leaves
the acid to join the alumine, and the lime
takes the acid. Hence as 4 of the alumine
enters into solution with the potash, the pre-
cipitate is less copious, and the liquid is alka-
line \ a small portion of acid put into the
clear liquid engages the potash, and liberates
the alumine, but a larger portion redissolves
the alumine also.
The sixth portion of lime-water seems to
complete the effect which the fifth commences,
and hence the density of the liquid increases,
whilst the precipitate rather diminishes.
The seventh portion of lime, together with
the sixth, after due agitation and some time,
unite the lime with the alumine, one atom of
Uu
346 APPENDIX
each, and form a precipitate which would fall
together, were no other compound present,
asT found, and Seheele before me; but if sul-
phate of lime be present, each compound
atom of lime and alumine, unites with one of
sulphate of lime, and the whole descends to-
gether, forming" a subsulphate resembling that
of alum, only two atoms of lime are found
as substitutes for two atoms of alumine. This
subsalt is very little soluble in water.
According to this view, if 2 atoms of alum
were decomposed, 4 atoms of subsulphate
would be formed, each consisting of 1 'acid,
2 lime, and 1 alumine ; also 2 compound
atoms of potash and alumine, and 6 atoms
sulphate of lime. But in the final arrange-
ment, it would seem, that 2 atoms of sulphate
of lime are again decomposed, and sulphate
of potash formed, the 2 atoms of lime com-
bining with the 2 of alumine, and then two
more atoms of subsulphate are formed, and
the final arrangement is 6 atoms subsulphate
precipitated, and 2 atoms sulphate of potash,
and 2 sulphate of lime remain in solution.
The facts above stated appear to me to
place the constitution of alum in a clearer
pointof view than any other 1 have seen.
They make no difference in the weights of
the several elements in 100 grains of the salt,
ATOMIC PRINCIPLES. 317
from what we have given in Vol. 1 ; only the
weight of the atom of alumine is here taken
to be 20 instead of 15, and we have 3 atoms
of it in 1 of ahim, instead of 4, as in the
former account.
ON THE PRINCIPLES OF THE ATOMIC
SYSTEM OF CHEMISTRY.
It is generally allowed that the great ob-
jects of the atomic system are, 1st to deter-
mine the relative weights of the simple ele-
ments 5 and 2d to determine the number, and
consequently the weight, of simple elements
that enter into combination to form compound
elements. The greatest desideratum at the
present time is the exact relative weight of
the element hydrogen. The small weight of
100 cubic inches of hydrogen gas, the im-
portant modifications of that weight by even
very minute quantities of common air and
aqueous vapour, and the difficulties in ascer-
taining the proportions of air and vapour in
regard to hydrogen, are circumstances suffi-
cient to make one distrust results obtained by
the most expert and scientific operator. The
specific gravity of hydrogen gas was formerly
estimated at ^ that of common air ; it de-
scended to 77^-, which is the ratio we adopted
848 APPENDIX*
in the Table at the end of Vol. 1 . It is now
commonly taken to be j~j9 and whether it
may not in the sequel be found to be 7*^7 is
more than any one at present, I believe, has
sufficient data to determine. The other fac-
titious gases have mostly undergone some ma-
terial alterations in their specific gravities in
the last twenty years, several of which 1 have
no doubt are improvements : but when we see
these specific gravities extended to the 3rd,
4th, and 5th places of decimals, it appears
to me to require a credit far greater than any
one of us is entitled to. In the mean time,
it may be thought a fortunate circumstance,
that the weight of common air has undergone
no change for the last thirty or forty years;
100 cubic inches being estimated to weigh
30. o grains at the temperature of 60°, and
pressure of 30 inches of mercury : (whether
this is exclusive of the moisture I do not re-
collect.) It is also a fortunate circumstance,
(provided it be correct) that this weight is
nearly free from decimal figures. I may be
allowed to add, that according to my expe-
rience, the weight of 100 cubic inches of air
is more nearly 31 grains than 30.5. I ap-
prehend these observations are sufficient to
shew that something more remains to be done
before we obtain a tolerably correct table of
ATOMIC PRINCIPLES. 349
the specific gravities of gases; the importance
of this object can not be too highly estimated.
The combinations of gases in equal volumes,
and in muhiple volumes, is naturally con-
nected with this subject. The cases of this
kind, or at least approximations to them,
frequently occur; but no principle has yet
been suggested to account for the phenomena ;
till that is done I think we ought to investi-
gate the facts with great care, and not suffer
ourselves to be led to adopt these analogies
till some reason can be discovered for them.
The 2d object of the atomic theory, namely
that of investigating the number of atoms in
the respective compounds, appears to me to
have been little understood, even by some
who have undertaken to expound the princi-
ples of the theory.
When two bodies, A and B, combine in
multiple proportions ; for instance, 10 parts
of A combine with 7 of B, to form one com-
pound, and with 14 to form another, we are
directed by some authors to take the smallest
combining proportion of one body as repre-
sentative of the elementary particle or atom
of that body. Now it must be obvious to
any one of common reflection, that such a
rule will be more frequently wrong than right.
For, by the above rule, we must consider the
350 APPENDIX.
first of the combinations as containing 1 atom*
of B, and the second as containing 2 atoms
of B, with 1 atom or more of A ; whereas
it is equally probable by the same rule, that
the compounds may be 2 atoms of A to 1 of
B, and 1 atom of A to 1 of B respectively ;
for, the proportions being 10 A to 7 B, (or,
which is the same ratio, 20 A to 14 B,) and
10 A to 14 B ; it is clear by the rule, that
when the numbers are thus stated, we must
consider the former combination as composed
of 2 atoms of A, and the latter of 1 atom of
A, united to 1 or more of B. Thus there
would be an equal chance for right or wrong.
But it is possible that 10 of A, and 7 of B,
may correspond to 1 atom A, and 2 atoms
B; and then 10 of A, and 14 of B, must
represent 1 atom A, and 4 atoms B. Thus
it appears the rule will be more frequently
wrong than right.
It is necessary not only t® consider the
combinations of A with B, but also those of
A with C, D, Er &c. ; as well as those of
B with C, D, &c, before we can have good
reason to be satisfied with our determinations
•s to the number of atoms which enter inta
the various compounds. Elements formed of
azote and oxygen appear to contain portions
©f oxygen, as the numbers ly 2, 3y 4, 5y sue-
ATOMIC PRINCIPLES. 351
cessively, so as to make it highly improbable
that the combinations can be effected in any
other than one of two ways. But in deciding
which of those two we ought to adopt, we
have to examine not only the compositions
and decompositions of the several compounds,
of these two elements, but also compounds
which each of them forms with other bo-
dies. I have spent much time and labour
upon these compounds, and upon others of
the primary elements carbone, hydrogen,
•oxygen, and azote, which appear to me to
be of the greatest importance in the atomic
system; but it will be seen that I am not sa-
tisfied on this head, either by my own labour
or that of others, chiefly through the want of
an accurate knowledge of combining pro-
portions.
352
APPENDIX.
NEW TABLE
OF THE RELATIVE WEIGHTS OF ATOMS.
At the close of the last volume, the weights of several
principal chemical elements or atoms were given ; but as
several additions and alterations have been educed from
subsequent experience, it has been judged expedient to
present a reformed table of weights;
SIMPLE ELEMENTS.
Weights.
Hydrogen I
Azote 5±, or 10 P
Carbone 5.4
Oxygen 7
Phosphorus 9
Sulphur ...13, or 14
Calcium 17 ?
Sodium 21
Arsenic 21
Molybdenum ...21, or 42?
Cerium 22?
Iron ...25
Manganese 25
Nickel 26
Zinc 29
Tellurium 29, or 58?
Chromium 32
Potassium 35
Cobalt 37
Weights.
Strontium 39
Antimony ....40
Iridium 42
Palladium '.. 50
Uranium 50, or 100?
Tin- 52
Copper 56, or 28?
Rhodium 56
Titanium 59?
Gold 60±
Barium 61
Bismuth 62
Platina 73
Tungsten .84, or 42 ?
Silver 90
Lead 90
Columbium ...107? 121?
Mercury 167, or 84?
SIMPLE OR COMPOUND
Weights
Fluoric Acid 10? J5?
Magnesia 17
Alumine 20
Glucine .23? 34?
Lime 24
Oxymuriatic Acid
(chlorine) 29 or 30
Muriatic Acid
Wrights.
} 30, or 31
Zircone 45
Silex 45?
Yttria 53? 36? 18?
RELATIVE WEIGHTS OF ATOMS. 353
COMPOUND ELEMENTS.
wdghts-
Ammonia 6? 12? L3r
defiant Gas 6.4? 12.8?
Carburetted ^
Hydrogen > 7.4
or Pond Gas J
Water 8
Phosphuretted 7 .„
Hydrogen j
Nitrous Gas 32, or 24?
Carbonic Oxide S2.4
Sulphuretted Hydrogen 15
Deutoxide of Hydrogen 15
Nitrous Oxide 17
Nitrous Acid ...19, or 38?
Carbonic Acid 19.4
Sulphurous Oxide 21
Phosphoric Acid 23
Sulphurous Acid 28
Protoxide of Arsenic ...28
Soda .28
H ydr ate of Lime 32
Protoxide of Iron 32
Protoxide of Man- }
ganese )
Protoxide of Nickel ...33
Sulphuric Acid 35
Sulphuret of Arsenic 7 q/-
(native) j JD
Hydrate of Soda 36
Oxide of Zinc 36
Carbonate of Magnesia 36.4
Protosulphuret of Iron 39
DeutoxideofManga~7 ^
nese 3
Oxide of Chromium ...39
Muriate of Magnesia... 39
32
Protosulphuret of
Nickel
Protosulphuret of
Lime
Carbonate of Lime
Protoxide of Cobalt
Strontites 46
Muriate of Lime ..46
Chromic Acid 46
Protoxide of Antimony 47
Xx
40
41
43.
44
Weights
Carbonate of Soda 47.4
Hydrate of Potash 50
Muriate of Soda 50
Sulphate of Magnesia 52
Sulphuret of Antimony 54
Sulphate of Alumine 7 -,
(simple) )
Oxide of Palladium .. 57
Sulphate of Lime 59
Protoxide of Tin 59
Carbonate of Potash. ..61. 4
55
62
Hydrosulphuret of 7
Antimony 3
Nitrate of M agnesia . . .62
Sulphate of Soda 63
Protoxide of Copper ...63
Muriate of Potash 64
Deutoxide of Tin 66
Protosulphuret of Tin 66
Oxide of Gold .. 67
Barytes 68
Muriate of Lime .69
Oxide of Bismuth 69
Deutoxide of Copper 70
Nitrate of Soda 73
Sulphuret of Gold 74
Protosulphuret of 7 -g
Bismuth 3
Sulphate of Potash 77
Oxide of Platina 80?
Nitrate of Potash ......87
Carbonate of Barytes 87
Muriate of Barytes ...90
Oxide of Silver 97
Protoxide of Lead 97
Minium ,...98
Sulphate of Barytes 103
Deutoxide of Lead ...104
Protosulphurets of 7 . ^.
Lead and Silver 3
Nitrate of Barytes ...113
Protoxide of Mercury 174?
Deutoxide of Mercury 181 ?
Protosulphuret of 7 1Q1 ?
Mercury j lbl
Alum .....277
354 APPENDIX,
ADDENDA.
Steel.— Since writing* the article at page
214, I have had an opportunity of analysing the
crystalline steel, formed by Mr. Macintosh's
process of cementation by means of coal gas.
I dissolved 21 grains of this steel in sulphuric
acid, with only a very slight excess of acid.
The whole was dissolved except about XV of
a grain of silvery-like particles. The gas
obtained amounted to 29.6 cubic inches. It
yielded no trace of carbonic acid. When
fired with oxygen it yielded 3 per cent, upon
the volume of hydrogen of carbonic acid ;
and this arose, as I ascertained, from the hy-
drogen containing 3 per cent of carburetted
hydrogen gas: it contained no carbonic ox-
ide. Supposing the carbone to have been
combined with the iron, it would amount
only to about -J- of a grain, to 100 grains
of iron. Whether such a quantity can be
deemed an essential or an accidental ingre-
dient of steel, may be a subject of consider-
ation.
MIXED GASES. 355
By a mistake of the Printer, the following paragraphs
were omitted after page 308.
EXAMPLE.
According to the following values of the dif-
ferent specific gravities, (of the accuracy of
some of which there may be doubts) and
referring to my essay on oil gas (Manchester
Memoirs, Vol."' 4, new series, page 79,) we
may take the oil gas, which, when the in-
combustible portion was abstracted would be
nearly .812 sp. gravity, and
100 pure gas give 152 carb. acid and take
24S oxygen ;
Here w = 100, a = 15% g = 248, S = 1.458,
/= .555, c = .972 s = .0694 and (7= .812.
The value of u reduces to the following form ;
„ 4.7916 a - If a -f 1.875 w - 6 C w Q . «
u = — ^— 625 = 24°
hydrogen per cent, of pure combustible gas.
Hence we have 75.5 volumes left for the 3
other ingredients = w of the formula; and
abstracting 12 + from the oxygen on account
of the hydrogen, g = 236 - , and a =152
as above.
356 APPENDIX.
Whence x =± Superolefiant =* 38*
y = Carb. hydrg. == 30.2
and z = Carb. oxide = 7-f-
75.5
These results differ considerably from those
deduced in the above essay ; probably in part
from errors in the above estimates of the spe-
cific gravities of one or more of the gases,
EXPANSION OF LIQUIDS BY HEAT.
I am not aware of any particular labour
that has recently been given to the enquiry
how far pure liquids accord with each other
in the law which I announced as derived from
the experiments on water and mercury, and
corroborated by those upon several other
liquids. See Vol. 1, Table of temperature,
page 14 ; also page 36, and following.
Perhaps all liquids should be considered as
pure that are subject to uniform congelation
at certain temperatures on the one hand, and
on the other are capable of being distilled by
heat without any alteration in their constitu-
tion. Water and mercury will rank in the
first place ; alcohol of .82 specific gravity
and ether of .72; concentrated sulphuric
EXPANSION OF LIQUIDS. 357
acid ; nitric acid of 1.42 specific gravity :
naphtha and oil of turpentine, &c. will pro-
bably be thought to claim the next place.
It is desirable that the temperatures at which
these liquids congeal should be ascertained ;
also whether any decomposition is effected
by the operation. If these expand propor-
tionally to a scale of square numbers for
certain given equal or unequal intervals of
temperature, it may point out something re-
lative to the collocation of the ultimate par-
ticles in liquids. The apparent coincidence
of this rate of expansion in liquids, with the
geometrical progressive force of steams or
vapours creates an additional interest. It
may be that most or all of these supposed
relations are accidental, and only approx-
imative like that of the rate of expansion of
air and mercury, between the temperatures
of- 40° and 212°; but I cannot think this
probable. Even should they be only approx-
imations, they are of sufficient utility to be
kept in view.
FINIS.
Printed by the Executors of S. Russell.
BOOKS, ESSAYS, &c,
PUBLISHED BY THE SAME AUTHOR.
Meteorological Observations and Essays.
4.5. 8vo. 1793.
Elements of English Grammar : or, a new
System of Grammatical Instruction, for the use
of Schools and Academies. 2s. 6d. 12mo. 1801.
£>• A few Copies of these Works may still be had of the London Booksellers.
A New System of Chemical Philosophy.
Part I. of Vol. I. Is. 8vo. 1808.
Part II. 105. 6d. 8va— 1810.
Published by G. Wilson, Bookseller, Essex-street, Strand, London.
ESSAYS, by the same, in ithe Memoirs of the Literary
and Philosophical Society, Manchester.
Vol. 5. Part 1. — Extraordinary facts relating to the vision
of colours.
Part 2. — Experiments and observations to determine
whether the quantity of rain and dew is equal to the
quantity of water carried off by the rivers, and raised by
evaporation ; with an enquiry into the origin of springs.
Experiments and observations on the power of fluids,
to conduct heat, with reference to Count Rum ford's
seventh essay on the same subject.
Experiments and observations on the heat and cold
produced by the mechanical condensation and rarefaction
of air.
Experimental essays on the constitution of mixed
gases; on the force of steam or vapour from water and
other liquids, in different temperatures, both in a Torri-
cellian vacuum, and in air ; on evaporation ; and on the
expansion of gases by heat.
i
ESSAYS, 8tC.
Meteorological observations made at Manchester, from
1793 to 1801.
Vol. 1. Second series. — Experimental enquiry into tile pro-
portions of the several gases or elastic fluids constituting
the atmosphere.
On the tendency of elastic fluids to diffusion through
each other.
On the absorption of gases by water and other liquids.
Remarks on Mr. Gough'stwo essays on the doctrine of
mixed gases ; and on Professor Schmidt's experiments on
the expansion of dry and moist air by heat.
Vol. 2. On respiration and animal heat.
Vol. 3. Experiments and observations on phosphoric acid
and on the salts denominated phosphates.
Experiments and observations on the combinations of
carbonic acid and ammonia.
Remarks tending- to facilitate the analysis of spring
and mineral waters.
Memoir on sulphuric ether.
Observations on the barometer, thermometer, and rain,
at Manchester, from 1794 to 1818 inclusive.
Vol. 4. On oil, and the gases obtained from it by heat.
Observations in Meteorology, particularly with regard
to the dew-point, or quantity of vapour in the atmos-
phere ; made on the mountains in the North of England.
On the saline impregnation of the rain which feli
during the late storm, December 5th, 1822 — with an
appendix to the same.
On the nature and properties of indigo, with directions
for the valuation of different samples.
In the Philosophical Transactions of the Royal Society.
On the Constitution of the Atmosphere. — 1826.
In Mr. Nicholson's Philosophical Journal.
Vol. 5. (Quarto) On the constitution of mixed elastic fluids,
and the atmosphere. — 1801.
Vol. 3. (Octavo) On the theory of mixed gases.
5. On the zero of temperature.
6. Correction of a mistake in Dr. Kirwan's essay on
the state of vapour in the atmosphere.
ESSAYS, k.C.
8. On chemical affinity as applied to atmospheric air.
9. Observations on Mr. Gough's strictures on the theory
of mixed gases.
10. Facts tending to decide at what point of temperature
water possesses the greatest density.
12. Remarks on Count Rumford's experiments on the
max. density of water.
13&14. On the max. density of water in reference to Dr.
Hope's experiments.
28, On the signification of the word particle as used by
chemists.
29 Observations on Dr. Bostock's review of the atomic
principles of chemistry.
In Dr. Thomson's Annals of Philosophy.
Vol 1 & 2. On oxymuriate of lime. — 1813.
3. Remarks on the essay of Dr. Berzelius, on the
cause of chemical proportions.
7. Vindication of the theory of the absorption of
gases by water, against the conclusions of M.
De Saussure.
9 & 10. On the chemical compounds of azote and oxygen,
and on ammonia.
11. On phosphuretted hydrogen.
12. On the combustion of alcohol, by the lamp with-
out flame.
On the vis viva.
In Phillips's Annals of Philosophy.
Vol. 10. (new series). On the analysis of atmospheric air
by hydrogen.
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